Revised June 2004
Affordable Sustainability Technical Assistance for HOME Project
Sustainable housing design is a multifaceted concept, embracing:
Only a holistic approach to design—one that considers and addresses each of these facets— can truly claim to provide a sustainable house.
At the same time, it's important to recognize the constraints that often affect real-world, rather than ideal, projects. Evergreen Affordability offers practical tools to use in building sustainable housing, based on experience with actual design and construction projects.
The City of Hazelton. For initiating the City's interest in the Pine Street Neighborhood, Hazleton Mayor Louis J. Barletta credits the efforts of city resident Bill Sherman. Nearly 50 years ago, Sherman relentlessly petitioned the Hazleton School Board to demolish the former Pine Street Elementary School and use the land to develop a playground, rather than reserving the plot for commercial development. Sherman's work did not go to waste, as the city has now invested $500,000 in upgrades for the playground, which has served as an anchor for the new Pine Street Neighborhood.
The City of Hazleton and its Office of Community Development have committed significant time, money, and effort to the project, including holding public meetings to gain input from citizens. The New Homes in the Pine Street Neighborhood strengthen the ongoing efforts of the "Alliance to Revitalize Center City Hazleton," a partnership of local government, the Chamber of Commerce and community development corporations committed to a re-energized downtown district. The Alliance has worked to upgrade buildings in the downtown area, bring in new businesses, and customers to the hub of the City. Nearly half of the acquisition costs for Pine Street were defrayed by Hazleton's Community Development Office. The balance of the property was acquired through actual donation of land by the property owners to the City, a factor which further signifies the community support of this undertaking. The City and its Community Development Office have committed additional dollars for infrastructure improvements, demolition, construction and other project related costs needd to bring this project to fruition. Another key role of the City has been to extend the arms of the partnership to encompass other key players that offer expertise and assistance.
Contact: Sam Monticello,
Hazleton, PA 18201
|Luzerne County Board of Commissioners serving as partners in the Pine Street Project are:
♦ Gregory A. Skrepenak, Chairman
♦ Todd A. Vonderheid
♦ Stephen A. Urban
Luzerne County, through its Office of Community Development and under the leadership of Ms. Sandra Russell, Director, has helped to ensure that Pine Street Neighborhood will serve as a model to be replicated throughout the Commonwealth of Pennsylvania and beyond. Recognizing the importance of working together with the City of Hazleton and its Community Development Office, Ms. Russell has brought forth valuable community building blocks through her involvement with the Luzerne County Consolidated Plan, Continuum of Care, and most recently, passage of the Affordable Housing Trust Act through the Luzerne County Board of Commissioners.
The Pine Street Neighborhood has received assistance through the Luzerne County Community Development Office with costs related to demolition, and has carried out required relocation activities. Financial assistance has also been provided for infrastructure, construction, and related project costs.
Through the establishment of the Act 137 Housing Trust Fund, along with the County's HOME Program, the County will offer financial assistance to prospective home-buyers. The County will administer Brownfields for Housing funds to further benefit the Pine Street Neighborhood. The County also successfully applied for a Department of Environmental Protection Environmental Energy Challenge Grant and aided in the application for the Pine Street endeavor.
The commitment of time, energy, and money by the County Commissioners, along with Ms. Russell and her staff, is worthy of special recognition and credit. The Pine Street Neighborhood would not have been successful had it not been for their efforts.
Luzerne County's Solid Waste Management Agency is researching sources of green materials to be utilized in construction. The Recycling Coordinator will work closely with HDC staff to insure that materials are readily available, thus eliminating construction delays. Not only will the New Homes in the Pine Street Neighborhood serve as a model for reuse of brownfield sites, as well as a model for resource and energy efficiency, but the County is committed to utilizing this project as a model for increased commitment to recycling and a demonstration of the benefits of purchasing recycled materials.
Contact: Ms. Sandy Russell, Director
Luzerne County Office of Community Development
54 West Union Street
Wilkes-Barre, PA 18711
The Housing Development Corporation of Northeastern Pennsylvania (HDC), a non-profit organization, is the developer for the new homes in the Pine Street Neighborhood. Gene Brady, President, has spearheaded efforts to develop Pine Street Neighborhood. It is their vision that has made the project a model for sustainable and affordable housing. The purpose of the Housing Development Corporation of Northeastern Pennsylvania is to further the goals of affordable housing for all Northeastern Pennsylvania residents by promoting and developing affordable housing. HDC has extensive experience developing and managing housing and is recognized by the Commonwealth of Pennsylvania, Department of Community and Economic Development as the Community Housing Development Organization (CHDO) for the City of Hazleton as well as the County of Luzerne. HDC has significant experience with homebuyer financing programs and also has a successful track record with the Pennsylvania Housing Finance Agency, and myriad of other housing activities and funding sources. HDC also provides homebuyer counseling, family savings program, budget management, prepurchase counseling and an assortment of other services key to prospective homebuyers.
Contact: Gene Brady, President
Housing Development Corporation of Northeastern Pennsylvania
163 Amber Lane
Wilkes-Barre, PA 18702
Voice: 570/824-4803 (voice)
Fax: 570/970.9193 (fax)
Design Coalition provided architectural schematic and design development services as well as consulting on project implementation for the Pine Street Neighborhood. Design Coalition Inc. is Wisconsin's only full-time non-profit architectural and planning office, and a Community Design Center. Design Coalition states "We don't work for profit; we have always sought ways to serve a greater community good through our professional practice. We work with our clients for a successful project, and for positive change." Design Coalition was founded with the mission of serving and empowering people who are without access to quality design and construction expertise. Today Design Coalition is a small office that still specializes in socially conscious and ecologically responsible design.
Borton-Lawson Engineering provided construction documents, bidding, and contract administration architectural services as well as landscape design, and geotechnical serivces for Pine Street Neighborhood. Since its founding in 1988, Borton-Lawson Engineering, Inc. has grown into a multi-disciplined professional engineering consulting firm.
The firm's staff includes civil, structural, mechanical, electrical and environmental engineers, as well as professional land surveyors. This team of professionals provides consulting services to industrial, commercial, institutional, governmental and private clients.
Contact: Pat Endler, Architect
613 Baltimore Drive, Ste. 300
Wilkes-Barre, PA 18702
570/821-1990 ext. 7903 (fax)
Fannie Mae contributed funding to aid in completion of the housing study and market analysis completed by Real Estate Strategies, Inc.
The Federal Home Loan Bank of Pittsburgh is providing funding to aid in construction activities through its Affordable Housing Program.
Janet Flack provided interior design consulting services for the Pine Street Housing.
Contact: Janet E. Flack, IIDA
242 West 8th Street,
Wyoming, PA 18644
The National Center for Appropriate Technology, (NCAT), provided technical assistance to the Pine Street Neighborhood in project development and sustainable design assistance. A non-profit corporation, NCAT was founded in 1976 to research, develop, and implement sustainable technologies to assist the economically disadvantaged. NCAT provides innovative information, training, and technical services to public agencies, grassroots organizations, and businesses.
The Center for Resourceful Building Technology (CRBT), a project within NCAT, is dedicated to promoting environmentally responsible practices in construction. Its mission is to serve as both catalyst and facilitator in encouraging sustainable and resource-efficient building technologies.
Affordable Sustainability Technical Assistance (ASTA) is a national technical assistance project funded by the U.S. Department of Housing and Urban Development HOME program. ASTA is designed to provide The Sustainable Energy Fund was created by the Pennsylvania Public Utility Commission in the electric utility restructuring. The Fund provides financing that promotes renewable energy, advanced clean energy technologies, energy conservation, and energy efficiency.
ASTA is designed to provide technical assistance to recipients of HOME grants in incorporating sustainable design into affordable housing.
The Pennsylvania Department of Community and Economic Development provided funds under the Communities of Opportunity Program, including Housing and Redevelopment funds for site restoration and development, and Brownfields funding for affordable housing activities on previously developed sites in core communities.
LDF Consultants served as liaison and expeditor between all parties and contracts.
151 East County Road
Drums, PA 18222
While a development is still in the idea stage, anything is possible. As an idea, it can be the most environmentally responsible, efficient, cutting edge, affordable housing imaginable. As the project progresses, though, reality hits, and the developer has to reconcile conflicting priorities with each other and with the real-world circumstances of the particular project, site and budget.
No single house can be a stellar example of every possible facet of affordable and green construction. In part, this is because some features or materials are only appropriate in certain climates or design styles. Also, different objectives sometimes may be in conflict with one another. For example, both indoor air quality and energy efficiency are worthwhile goals, yet ventilating a house to improve indoor air quality reduces its energy efficiency somewhat. The two goals have to be balanced with one another to arrive at an optimal solution. This kind of compromise means that on any given project, some goals may be unattainable. In addition to having to reconcile diverse goals, most projects face budget constraints that may rule out the choice of some materials or technologies. That doesn't mean that affordable, environmentally responsible construction isn't possible; it simply means that coordinated planning and a unified approach to design are vital to achieving exemplary green construction in an affordable home.
Some of the priorities a project might have include:
It's best for the developer and design team to determine and agree upon their top priorities at the outset of the project, so they know where they can afford to compromise and where they want to hold the line. Otherwise, the development's conflicting priorities are all likely to be compromised, resulting in a watered-down project that doesn't truly achieve any of the original goals the developer envisioned. Prioritizing goals helps to streamline the decision-making process during both the design and construction phases of the project.
Sometimes it's difficult to achieve project priorities because they're not well defined. What the developer considers "energy-efficient" may not be the same equipment or air sealing practice that the builder calls "energy-efficient." In order for the project priorities to be carried through the design process and executed in the building as it's constructed on the ground, it may be useful to adopt some clearly-defined standards that everyone recognizes.
These may be standards that are mutually agreed upon by the design team and included in written form in the project specifications. Alternatively, the developer and design team may opt to create a development that meets an objective, independently-set standard. This helps everyone involved in the project understand precisely what the goal is and what steps must be taken to reach it.
One widely-accepted national standard for energy performance is provided by the Energy Star program. In order to achieve an Energy Star rating, houses must meet specific performance requirements that show them to be 30% more efficient than standard construction for the area. Designing and constructing houses that meet Energy Star qualifications is one good way to ensure that an affordable development will be energy–efficient.
In some parts of the country there are green building programs that provide checklists or rating systems for environmental considerations. These may address energy and resource efficiency, job-site waste reduction and water efficiency, as well as other facets of a project. In areas where such programs exist, they provide a convenient means of gauging the "greenness" of a project and providing targets for a project to strive towards. Many designers are looking forward to the day when the U.S. Green Building Council unveils its LEED standard for residential buildings, which will offer a nationwide standard for green homes. Until then, developers in areas without local green building programs may have to borrow the checklists and guidelines of other programs in similar climates to provide a benchmark for their projects.
Several green building programs across the country offer their checklists and evaluation criteria online. Check with state and local home builders associations, energy offices and building departments for green building programs that may be applicable to your project.
The design and construction of sustainable buildings should be an integrated process, involving a design team that ideally includes the owner/developer, designer, engineers and the builder. Generally, it's easier to build a sustainable building if at least one member of the design team has experience with green building. Since many traditional design firms have limited experience with sustainable design, a consultant who specializes in sustainable building can be a worthwhile addition to the team. Team members with experience in green building will be at least somewhat familiar with the possible strategies for sustainability and potential material options. They can help the project avoid pitfalls and costs associated with extra research and learning curves, because they won't be starting from square one.
However, one team member alone can't make a building sustainable. It is essential that all team members work together in a holistic approach. Because a house is a complex combination of systems, it is vital that all the systems be integrated and balanced to complement one another in achieving maximum efficiency. For example, improving the energy efficiency of a building shell often means that the heating/cooling system doesn't have to be as large—but the mechanical designer needs to be made aware of the opportunity to downsize equipment, the structural designer has to include room for insulation in walls and roof, and the builder has to use proper installation techniques.
Many developers who have successfully completed affordable green building projects have issued requests for qualifications (RFQs) or requests for proposals (RFPs) that specifically seek designers, consultants and builders with experience in sustainable design. In particular, a request might specify that respondents must comply with one or more of the following, as appropriate for the job and the location:
In addition, the developer might ask that the respondents provide evidence of their expertise in fields that are priorities for the project, such as:
A local firm with genuine enthusiasm for learning about sustainable design may offer the best value for the nonprofit affordable housing developer even if they don't have a great amount of experience in green building. Community connections, familiarity with the climate and site, willingness to learn more about sustainable building, and the ability to be on site regularly can go a long way toward offsetting a lack of prior green building experience. However, employing alternative building materials or innovative new systems is greatly simplified and usually less costly if the design team has a proven track record using them.
As soon as project priorities are determined, they should be included in all RFPs, RFQs and bid documents throughout the remainder of the project. This helps ensure that the design and construction team share the same expectations for the project.
Selecting an architect and design team is one of the most important steps toward a successful building project. There are two types of firms that should be considered for a sustainable project. The best choice is a firm with a proven track record of sustainable design, with several projects that demonstrate their experience and commitment to sustainable design. The other type of firm that could be considered is less experienced with sustainable design but can convince the selection committee that they are eager and willing to learn about the design patterns and construction techniques associated with this type of project. In some areas of the country there are few, if any, firms experienced with sustainable design and a less-experienced firm may be the only alternative.
The following questions can be modified by each project selection team to include local issues and concerns.
In the most simple and typical affordable housing project, the owner/developer hires an architect who designs the project. The architect may hire a mechanical, structural or electrical consultant to assist with the design. Depending on the nature of the project, an interior designer and landscape architect may also be involved with the project. After the project is put out for bid, a single general contractor is selected to construct the project. This basic model will work well for many projects, although a number of affordable housing developers are trying other approaches that may include special consultants and material-purchase options. You may find these approaches useful for your projects:
Green Design Consultant
In cases where the local architects have little experience with sustainable design, a sustainable design consultant can be added to the design team. This consultant can work directly for the owner or as a consultant to the project architect. In most cases, the consultant will work as a subcontractor to the primary architect. Firms who have little experience with sustainable design would be well-served by adding a sustainable design consultant to their proposal.
For the Pine Street Neighborhood development in Hazleton, Pennsylvania, an out-of-state architect was hired to perform schematic and design development services and a local architect was hired to perform the construction documents, bidding and administration services. The owner negotiated separate contracts with each firm, with much attention given to defining the specific roles of each firm.
Owner/Developer Material Purchase
In the typical construction contract utilizing a general contractor, the contractor adds 10% to 20% to all project costs for overhead and profit. The materials purchased for construction projects are subject to sales taxes in most states.
In Wisconsin and Pennsylvania, though, it is possible to negotiate a contract that allows an entity such as a nonprofit organization or local government to purchase the major materials to avoid paying the sales tax. In Pennsylvania, state law prohibits the non-profit community housing developer from fulfilling this role, so on the Pine Street project the local community development corporation purchased the construction materials.
In this case, the bid package was prepared to clarify the role of the contractor relative to material purchases, scheduling delivery and coordination. The three bidders on the Pine Street project did not mind this approach to material acquisition. Obviously, the bid documents and bid form must be carefully crafted to deal with this non-standard approach to purchasing.
If this approach is considered, state law should be investigated to see if it is possible to avoid the sales tax on material purchases by either non-profit developers or an arm of the local government.
Owner/Developer as General Contractor
It is also possible that the Owner/Developer would act as the general contractor for the entire project. For this approach to be successful, the Owner/Developer would have to employ staff capable of performing the role of general contractor. By taking on this responsibility, the Owner/Developer is betting that they can do the job as well as a general contractor to avoid paying the profit charged by the private firm.Some funding sources may require that a development project incorporate competitive bidding. The regulations that are associated with each type of funding must be carefully examined for potential conflicts with the Owner/Developer acting as general contractor.
In 2001, the Housing Development Corporation of Northeast Pennsylvania, a non-profit housing developer, began the Pine Street Neighborhood Revitalization in partnership with the City of Hazleton and Luzerne County. "New Homes in the Pine Street Neighborhood" began developing 24 new homebuyer opportunities geared toward a diverse audience with a range of income levels, as part of an overall revitalization program of the City of Hazleton.The Pine Street Neighborhood utilizes state-of-the-art design techniques to integrate health, accessibility, operational efficiency, low maintenance, functional living space and aesthetic appeal. This affordable, sustainable development is about renewing a sense of community and traditional values, intertwining the charm of a small town environment with the latest design and construction technology.
The Pine Street Neighborhood was able to take advantage of free affordable sustainability technical assistance services offered to HUD HOME grantees by the National Center for Appropriate Technology under a grant from HUD. In addition, the Housing Development Corporation paid for additional green building consulting and design services to help make the project more sustainable and energy-efficient.
Hazleton was incorporated as a borough in 1856. The borough's population grew steadily until the 1880s when waves of eastern European immigrants poured in to take jobs created by the booming coal industry.In 1891, Hazleton was chartered as a city. In the early part of the 20th Century, Hazleton was a boomtown, its population increasing from 14,230 in 1900 to 25,452 in 1910. The population would peak at 38,009 in 1940. With the decline of the anthracite coal industry the city's population decreased.
its access to major highways, a dedicated work force, a low cost of living, and a high quality of life. This includes a commitment to excellence in the arts, education, recreation and health care.
Hazleton is a city with a wealth of municipal services, a revitalized downtown that is the center of banking and professional services, mass transit and many of the amenities associated with city life, but few of the problems. The crime rate, for example, is eighth lowest in the entire nation. The Hazleton downtown area combines a charming small-town environment, traditional values, and modern conveniences. Together, they form a complete package that makes the Pine Street Neighborhood a great place to live, work and play.
New Homes in the Pine Street Neighborhood are being constructed on a three-block site adjacent to downtown Hazleton, bounded by Fulton Court and Hemlock, Pine and Green streets. This once-lively turn-of-the-twentieth-century industrial, commercial and residential neighborhood has felt the full impact of economic distress with the obsolescence of its industrial buildings and deterioration of its housing stock. Ultimately the three-block area became a site of debris, decaying and abandoned residential and commercial structures, and substandard housing. The economic distress was creeping outward to impact surrounding properties. Returning this brownfield site to active use is a success story waiting to happen.
The Pine Street Neighborhood is an exciting opportunity to view a neighborhood as a cohesive unit, where adults and children can walk to nearby shopping, services, schools, parks, recreation centers and in some cases their own jobs and businesses; where public transportation is readily available; where houses are built close together, with yards. The pedestrian-friendly environment helps facilitate community spirit and emphasize neighborhood safety and security.
The Pine Street Neighborhood encourages "smart growth" by utilizing existing infrastructure and services in an already-developed area rather than contributing to suburban sprawl. New Homes in the Pine Street Neighborhood can make use of existing power, water and road infrastructure. The city saves the significant costs of extending municipal services like fire, police, transit and road maintenance beyond their existing territory. In addition, the site enjoys easy pedestrian access to downtown businesses and mass transit, as well as an adjacent park with playground and sports courts.
While the Pine Street Neighborhood will be a one-of-a-kind asset to Hazleton, it follows a national trend of builders to locate housing close to urban areas, since young families, single professionals and older Americans with grown children recognize the value of living in a diverse and active neighborhood with city amenities. A young family will benefit from the local park that features a playground, basketball court and soccer/hockey court. The park is well lit to allow for evening sports activities.
Sidewalks will be lined with trees and short lampposts. Crosswalks will be handicap accessible and intersections may be designed with materials to alert drivers that children will be in the area. A "walkable" neighborhood like this one builds a sense of community among residents, and helps the city avoid traffic congestion, road maintenance and air quality problems that are associated with suburban sprawl and the increased auto use that accompanies it.
Pine Street Neighborhood will attract many different kinds of residents. Such diversity helps create a vibrant neighborhood and build a sense of community. Additionally, new development on Pine Street complements other Hazleton revitalization programs, like building façade improvement, and meshes with the city's economic development and community vitality goals. Also, new residents in the neighborhood provide an expanded market for the area's retail and service businesses.
The Pine Street Neighborhood homes offer: Universal Design Healthy Living Maintenance-free Lifestyle Resource Efficiency for a Healthier
Environment Energy Efficiency for Reduced Costs and Increased Comfort.
Accessible, adaptable, and universal are terms now used to refer to housing or features in housing intended for use by people with disabilities and others. The term accessible, as
Universal Design for Greater Accessibility
generally used, means that the dwelling meets prescribed requirements for accessible housing as defined by the Americans with Disabilities Act (ADA), building codes, or in agency regulations or standards such as the American National Standards Institute's A117.1 and the Uniform Accessibility Standards (UFAS). Most of the features in "accessible" design are permanently fixed in place and clearly recognizable.
Some people for whom accessible features are not essential, dislike the appearance of such items as knee spaces under sinks and counters and grab bars in bathrooms or reduced base cabinet space. The term adaptable refers to a living unit with features that a fixed accessible unit has but allows some items to be omitted or concealed until needed, so the dwelling units can look the same as others and be better matched to individual needs when occupied.
Items that are usable by most people regardless of their level of ability or disability can be considered universally usable. Many accessible and adaptable features are universally usable. For example, round doorknobs are not usable by people with limited use of their hands, but lever handles are usable by almost everyone, including people who have no hands. Some items are made more universally usable by their placement. Making them adjustable makes some features more universally usable. Universal design addresses the scope of accessibility and suggests making all elements and spaces accessible to and usable by all people to the greatest extent possible. By incorporating the characteristics necessary for people with physical limitations into the design of common products and building spaces, we can make them easier and safer for everyone. Designers of the Pine Street Units have incorporated universal design throughout the project.
In the Pine Street Neighborhood housing universal accessibility offers the "home for a lifetime" aspect to home ownership, eliminating the need for households to renovate or relocate if someone in the family has or develops mobility impairments. Not just the interiors of many of the homes, but also the sidewalks, yards and parking will be designed to be fully usable by people with mobility impairments.
This means that all neighbors will be free to visit and join in the life of the community regardless of their physical limitations.
Each of the homes will be created with kitchens, bathrooms and dining rooms on the first-floor levels. "Jog-in walls" in the garages, which enable wheelchair accessibility, the lack of a front step and wider doors are some of the accessible aspects. First floor interiors, garages, sidewalks, yards and parking throughout the entire project are designed for full accessibility to people with mobility impairments. This universal design consists of subtle variations on standard design. Doorways are wider, wall outlets higher, kitchen cabinets lower and bathrooms designed for accessibility. Each dwelling unit is designed to provide wheelchair circulation accessibility of the first floor, from grade and from the garage, including the kitchen, dining and living spaces and at least one bedroom. One area where these homes will stand out is in using materials that promote good indoor air quality. Choosing the right building materials and ventilation systems will be a high priority.
By making healthy building materials and practices a priority, the Pine Street Neighborhood's new homes will promote good indoor air quality, contributing to the health of residents.
The Pine Street homes will focus on less-toxic building materials and interior finishes, as well as ventilation systems, to ensure good indoor air quality, an issue strongly supported by the American Lung Association and the Environmental Protection Agency.When we're talking about affordable housing, we are referring to long-term affordability beyond just the purchase price. We're not only considering energy costs, but durability as well.
A Maintenance-free Lifestyle
Durability and low-maintenance will be hallmarks of the Pine Street Neighborhood Homes. That also contributes to time savings and energy efficiency for homeowners. What's more, it will help keep the neighborhood looking good for a long time. Durable, low-maintenance building products
are an environmental benefit, as well as a time and energy savings to homeowners. Materials that require little maintenance don't add unexpected costs to homeowners' budgets. Eliminating the need for replacement materials is also a resource and energy savings.
Use of fiber cement siding is just one design feature that will result in long life of the building envelope. Meanwhile, installation of a heat recovery ventilator will help assure that there is not long-term damage to the building envelope from penetration of water vapor. The recycled roofing will provide more than double the lifetime than a traditional asphalt shingle roof. The energy-efficient design will assure that costly energy improvements will not be necessary over the life of the home. New Homes in the Pine Street Neighborhood feature sustainable materials that provide a range of benefits to the neighborhood residents and to the Hazleton community as a whole. For example reused and recycled building materials
save the energy and resources that would be used in obtaining and processing new materials.
Reused and recycled building materials help keep waste out of landfills by turning it to productive new uses. Pennsylvania companies offer some resource-efficient building materials and by using them, the Pine Street Neighborhood contributes to the local and state economy. Opting for regionally produced materials also prevents the expense and pollution that accrues when building products are transported from far away.
Roofing shingles for the Pine Street Neighborhood will be made with recycled tire rubber and recycled plastic. Carpeting will be produced from recycled plastic fiber. Brownstone from the foundation walls of the former Geissler Knitting Mills facility will be used to build retaining walls near the playground.
These new homes feature numerous sustainable materials that are more abundant and cause less environmental impact in their production. Examples of green materials that will be used in construction include fiber cement siding, cellulose insulation, and less-toxic finishes. In addition, the contractor will use a waste management plan to reduce the generation of waste during construction.
The Pine Street Neighborhood Homes will combine energy-efficient materials and systems to offer their owners low operating costs. Energy-efficient construction saves money usually 30 percent over standard construction.
That stretches household budgets, making energy-efficient houses a real boost to providing reasonably priced homes. Some mortgage lenders actually offer special energy-efficient mortgages that take into account the reduced household energy costs when they factor loan amounts.
An electrically heated home built in Hazleton to the current state energy standard, the International Energy Efficiency Code, will use
53.2 mmbtu of energy at a current cost of $1,499 per year. By contrast, the Pine Street units will use only 24.7 mmbtu annually, cost $1,119 per year and meet ENERGY STAR.
A natural gas heated housing unit built in Hazleton to the International Energy Efficiency Code would use 88.9 mmbtu of energy at a current cost of $1,130 per year. In comparison the Pine Street units that meet ENERGY STAR will use just 25.6 mmbtu and cost $799 per year. These units would be constructed with a whole-house ventilation system.
Well-built energy-efficient homes help residents stay cool in the summer and warm in the winter. The extra insulation and air sealing that make a home energy efficient also keep it quiet in a busy urban neighborhood. Cross ventilation stemming from the installation of diagonal windows could eliminate the need for air conditioning—which will also help reduce energy expenditures.
The Pine Street Neighborhood includes trees and yards that not only make it an attractive place to live, but also contribute to summer cooling. A well-recognized way to combat the urban heat island effect that makes cities uncomfortably hot in summer is to include green vegetation in landscaping plans. Trees contribute both shade and an evaporative cooling effect. Also green areas help cities manage storm water runoff that can tax water treatment facilities.
The Pine Street homes are oriented to allow for solar electric and solar water heating systems, with building roofs sloped at 45 degrees to accommodate solar installations, and to emulate the steep roof pitches of surrounding neighborhood dwellings.
One of the most resource-efficient development affordable, sustainable development to be built strategies is to rehabilitate an existing building on an already-developed site. This helps avoid on an already-developed site. This not only urban sprawl, gives the development's future preserves the value of the materials in the occupants access to services and allows the existing building, but also avoids the developer to avoid the costs of infrastructure consumption of new building materials in the extension. creation of a new building. Unfortunately, it's not always possible to reuse existing buildings. Sometimes there are no buildings on a site. Other times, it may be more costly to renovate a damaged, contaminated or unsuitable existing building than to build new. In this case, it is usually desirable to deconstruct the existing buildings and save as many materials as possible for reuse.
The site of the Pine Street Neighborhood project was carefully chosen. This site offers residents easy access to public transit, Hazleton's municipal services and an outstanding park recreation
Even in cases where existing buildings or materials can't be saved, it makes sense for an didn't coincide well with the Pine Street Revitalization's program of providing affordable, single-family housing for purchase. Consequently, all existing buildings were cleared from the site before new construction began.
The bricks from the old industrial buildings proved too soft to be cleaned and reused. However, all large timber beams and posts were salvaged and sold by the demolition contractor. In fact, the demand for reused timbers is so high all the timber was sold for reuse in the Philadelphia area before the actual deconstruction on the Pine Street site began. The brownstone used in the foundation in one of the buildings was also salvaged and will be reused in site work at the neighborhood playground and on the adjacent block of the Pine Street project.
Installing rigid foam insulation on the exterior walls of a home is an effective way to reduce conductive heat loss through the framing members and enhance the home's thermal performance. Rigid insulation can be installed on the interior or exterior of the wall framing, depending on preference and the climate where the home is being constructed. Either way, installing rigid insulation can provide substantial energy savings over a wood-framed wall with insulation in the wall cavity alone. Some of the advantages and disadvantages of each installation strategy are summarized below. The climatic considerations relating to where in the wall rigid insulation should be installed are discussed in depth on the Building Science Corporation website at http://www.buildingscience.com.
Exterior rigid insulation provides an effective barrier to water penetration into the wall. It minimizes moisture accumulation and the potential for damage to the exterior wall. The exterior insulation also helps to keep the wall cavity warmer and improves its drying potential. Research has shown that walls with exterior insulation have significantly lower moisture levels than walls without it.
In another possible assembly, rigid insulation is substituted for the structural sheathing. In this case, if the siding chosen is not structural you will need to provide separate bracing for the structural support of the exterior wall. Buildings of two stories or less can employ diagonal bracing of either wood or steel. The Uniform Building Code may be consulted for bracing requirements for residential buildings, as well as applicable local seismic codes.
Rigid insulation installed on the interior of the wall provides the same overall R-value as the exterior installation. Applying the rigid insulation on the interior allows normal framing and cladding of the exterior wall. It also allows the rigid insulation to act as the vapor retarder in the wall assembly, if the insulation has a perm rating of less than one. Taping or caulking the seams of the rigid insulation, as well as sealing it to the ceiling and floor, will form a continuous air barrier.
As with exterior rigid insulation, special attention is needed to provide backing for drywall and nailers around windows, doors, corners and wall intersections. The locations of exterior wall studs need to be marked on the foam as it is installed, for the drywall installers to follow. In addition, electrical boxes and plumbing stubs need to be adjusted due to the extra thickness of the wall due to the interior insulation.
|The architectural consultant on the Pine Street Revitalization Project specified an interior application of 1" expanded polystyrene (EPS) rigid insulation on the exterior walls. The extra 1" of EPS increased the total wall R-value by 4.2, in addition to reducing the thermal bridging between exterior wall studs and the interior drywall, which improves the whole-wall thermal performance.|
When designing an energy-efficient house, efficient heating and cooling systems are always high on the list of desirable goals. If a house is designed well to maximize the solar gain to its advantage in the winter and to limit solar gain in the summer, and it is properly insulated, then both the heating and cooling requirements are reduced. When systems for an efficient house are properly sized, they might be downsized from the standard system or not needed at all. This is particularly true with cooling systems for moderate or cold climates.
In moderate and cold climates, there are only a few times during the summer when the interior house temperatures might require air conditioning for occupant comfort. In those instances, the cooling requirements might be addressed with a room or spot air conditioner rather than central air conditioning. Spot air conditioning allows rooms that are frequently used—such as the dining and family room—to be cooled as needed when they are occupied, thus eliminating the need for a whole-house system.
Room air conditioners are used only when they are needed. They cost less to purchase, but are usually less efficient than central systems. Most use normal house voltage and can be easily moved to where they are needed.
Central air-conditioning systems are either packaged or split systems. Both circulate cool supply air and warm return air through a ducted system. If a house has a ducted heating system, a split system is the most economical form of air conditioning to install. The split system would use the existing furnace duct work and blower with an evaporator attached and have an exterior unit that houses the condenser and compressor.
On the other hand, packaged central air-conditioning systems are typically used for small commercial applications. They usually have a cabinet mounted either on the roof or on a concrete slab adjacent to the building, with the evaporator, compressor and condenser in it. Supply and return ductwork go through the building envelope to the unit. Most packaged systems also have electric heating coil or natural gas furnaces included. This eliminates the need to install separate systems for heat and cooling.
The Air Conditioning Contractors of America (ACCA) and the American Society of Heating, Refrigerating, and Air Conditioning Engineers (ASHRAE) publish procedures to properly size central cooling systems. Any reputable installer will use one of the above procedures to size a system for your house.
Each type of air conditioner has an efficiency rating as to how many Btu per hour it removes per watt power used. The efficiency rating for room air conditioners is the Energy Efficiency Ratio or EER. The central system efficiency rating is called the Seasonal Energy Efficiency Ratio or SEER. Either efficiency ratio should be displayed on the Energy Guide Label of the unit.
Recent advances in cooling equipment have allowed air-conditioning systems to be 30% to 50% more efficient than comparable models built in the 1970s. Even air conditioners that are 10 years old can now be replaced with new units that are 20% to 40% more efficient. National appliance standards require new room air conditioners be at least an 8.0 EER or greater. Central system air conditioners require a SEER of 9.7 for packaged systems and 10.0 for a split system. Many manufacturers have systems available that approach SEER 17, and most air-conditioning manufacturers are now participating in EPA's Energy Star Program, offering high-efficiency EER and SEER models that are Energy Star-certified.
Air conditioners can cool a room or house fairly quickly. For maximum energy savings, operate only when the house is occupied. Programmable thermostats on central systems are a good idea. Keep drapes and blinds on the east, south and west windows closed during the day to reduce unwanted solar gain.
|Houses in the Pine Street Neighborhood were designed and oriented to maximize winter solar gains and to limit summer gain. High insulation levels and strategic placement of windows will help limit radiant heat gain to houses. Consequently, the design team and developer decided not to install central air-conditioning systems at Pine Street, since their use would be limited in such efficient homes. With such infrequent use, installing central air conditioning would not be cost effective. Lists of Energy Starlabeled room air conditioners will be supplied to the new homeowners, for individuals who decide to install supplemental spot cooling.|
Compact fluorescent lights (CFLs) are far more In order to ensure that the homeowner efficient than standard incandescent light bulbs, continues to use compact fluorescents, the using only about a quarter as much energy to developer may choose to install dedicated CFL produce the same amount of light. Although the fixtures, rather than CFL bulbs in standard bulbs themselves are more expensive to fixtures. While the dedicated fixtures help to purchase, the CFLs last as much as ten times promote the long-term energy performance of longer than standard bulbs and operate at higher the home, they may be responsible for efficiency, so in the long run, they construction cost increases. Because save the homeowner money. There are relatively few dedicated CFL fixtures on the market, the choice of With the wide range of CFLs available styles is limited and prices may be today, it is possible to install a higher than for standard light fixtures. compact fluorescent bulb in almost any fixture to improve its energy Furthermore, the developer faces the performance. Developers can issue of how many hard-wired light completely outfit their new homes fixtures to provide with the home, and with CFLs before sale. Yet the how much lighting to leave to the future developer has no assurance that a owner's discretion. It is often the case home's future owner will continue to that only a few hard-wired light fixtures buy and use CFLs as bulbs burn out over time. are included in the home as sold. This limits the With the wide range of CFLs available today, owner's ability to influence lighting efficiency. in varying quality and widely varying prices, the homeowner may find selecting CFLs an In one affordable, sustainable development, the unwanted burden. If future owners purchase developer chose to include hard-wired inefficient replacement bulbs, this could dedicated compact fluorescent fixtures in the compromise the home's future energy kitchen and bath, while encouraging residents performance and operating cost. to use CFLs in other household lighting.
At the Pine Street Neighborhood, the design team debated where and how to incorporate CFLs in the homes. They considered specifying some dedicated hard-wired CFL fixtures, but found these specialized fixtures to be considerably more expensive than standard fixtures. The developer finally decided to supply the homes with CFL bulbs installed in the standard hard-wired fixtures in major living spaces.
Affordable housing developers have their choice of several strategies that can reduce the resource consumption of foundations. These are worth consideration because they reduce environmental impacts, such as carbon dioxide emissions, that stem from the production of cement, and because they often reduce construction costs, as well.
A simple foundation footprint based on even size increments reduces both foundation labor and material costs. Interest can be added to a home's design by using above-grade bump-outs and bays. These are generally less expensive than footprint modifications that increase foundation complexity, cost and resource use.
Replacing a portion of the cement used in concrete with fly ash is a means of reducing the energy and emissions involved in the manufacture of cement. Coal combustion fly ash, a by-product of electricity generation, is a pozzolan that can replace 18%-50% of the cement used in concrete, depending upon the application. Fly ash is ASTM listed (C-618 and C-311) and approved as a mineral admixture for use in mortar, patching, and structural concrete. In some areas ready-mix concrete companies supply fly ash concrete as a matter of course; in other areas the builder will have to request it specially. Fly ash concrete takes longer to reach its full cured strength, but ultimately provides a strong product with a smooth finish, made from recycled material.
Requiring reusable forms for any poured-in-place concrete is a good way to cut the amount of construction waste generated on site. The only job that should be exempt from using reusable forms is one where permanent insulating forms are used for the footing and wall system.
One of the most resource-efficient foundation systems available to builders is the frost-protected shallow foundation (FPSF). Rather than extending foundation footings below the frost line, this system relies on rigid foam insulation at the foundation perimeter to retain heat below the building slab, thus preventing frost heaves although the foundation is as little as 12" deep.
The FPSF system, developed in Scandinavia, has been used by some builders in the United States for decades, and is included in the International Building Code. Both the U.S. Department of Housing and Urban Development and the National Association of Home Builders have researched the frost-protected shallow foundation and published materials on its design and use. The FPSF has been a particular favorite among builders of affordable housing, because it greatly reduces the excavation and backfill costs associated with a conventional foundation, especially in a cold climate where the frost line is deep. This can provide a substantial savings.
The houses at Pine Street are designed with basements, in part because this was the regional standard. The basement provides an out-of-the-way location for the furnace and utility room, and could later be finished to provide additional living space if needed. Frostprotected shallow foundations cannot be used in conjunction with basement construction.
Over 90% of American residential construction has walls framed with dimensional lumber. It takes careful planning and design to achieve the goals of improved thermal performance, comfort, structural integrity for natural disasters, security, fire safety, durability, or just keeping building costs low. Fortunately, energy-efficient walls can be constructed in many ways and with a variety of materials. However, choosing between materials and the different ways to assemble them can be difficult.
There are many possible choices for insulation types: fiberglass batts, blown-in fiberglass, spray cellulose and foam are a few of the most popular. Wall assemblies can range from standard stick framing assembled on site to several types of pre-assembled panels.
Developers, designers and builders need to weigh the merits of the different wall system options available. One way of evaluating the energy performance of differing wall systems is to compare the R-values they provide. The most accurate way to do this is by comparing each system's "whole-wall R-value." The whole-wall R-value takes into consideration not just an insulated section of wall, but also all of the wall interfaces including the window and door openings, as well as the floor, wall and ceiling intersections. In addition, the whole-wall R-value includes what is called the "framing factor," which accounts for the thermal bridge that each wooden framing member provides through the wall assembly. Systems with fewer framing members, or an exterior layer of insulation, will have less performance loss than assemblies with many framing members. The whole-wall R-value is almost always lower than the stated wall R-value for any assembly, but for some it can be dramatically less.
To make it easier to compare various wall systems or components used in a wall, Oak Ridge National Labs has developed a "Whole Wall Thermal Performance Calculator." It is available to anyone at http://www.ornl.gov/roofs+walls/whole_wall/wallsys.html. The program accepts a simple description of custom building plans and enables the user to compare uniform whole-wall R-values for at least 40 different wall systems.
Calculators like this one help a design team evaluate the effect that different types and levels of insulation can have on a building's energy performance. In addition, the designers can predict how different structural assemblies will affect thermal performance. Calculators show how advanced framing techniques, which combine wider stud spacing with additional wall insulation, not only reduce wood use, but also improve whole-wall R-values.
At the Pine Street Neighborhood, the design team made several recommendations aimed at improving whole-wall R-values. They recommended consideration of structural insulated panels, a wall system with greatly reduced use of framing lumber, minimal thermal bridges and good thermal and sound performance. However, recognizing that the cost of structural insulated panels is often above the budget of an affordable housing project, the design team also suggested some strategies for producing more efficient wood-framed walls.
When building a new house, the selection of heating fuel can be an important factor in determining both construction and future operating costs. For an energy-efficient house, heating fuel type is still important, but less so. If the shell is properly insulated and sealed and energy-efficient windows and doors are used, the heating system can be downsized. If a high-efficiency unit is selected, the system can be even smaller, using even less fuel. When a minimal amount of fuel is used, variations in the cost of fuel types become less significant to the homeowner.
Prior to the mid-1970s energy crisis, developers and builders commonly built houses with minimal insulation. They also heated them with whatever fuel was available: heating oil, natural gas, propane or electricity, depending on region and whether the building site had access to a particular fuel. For some locations, fuel choice was quite limited. When energy prices started to rise, owners of inefficient homes saw enormous increases in their energy bills. Some increases were as much as 50% to 100% at that time, and prices have risen steadily since.
In most parts of the country, electricity is more expensive than fossil fuel for heating. Many homeowners have switched to fossil fuel heat. Decisions to switch heating systems and fuels are frequently based on monthly utility bill savings rather than long-term cost effectiveness. During the winter of 2001, the price of natural gas—usually the least expensive heating fuel—more than doubled in some areas. Although prices have again declined, uncertainty about international oil prices will make accurate prediction of future energy prices very difficult. Usually the costs of extending the fossil fuel distribution system (the pipes) along with the cost of a new heating system are more than the average homeowner will recoup in savings during the time they own a home.
In response to the potential loss in market share from customers switching to fossil fuels, many electric utilities seized the opportunity to promote energy conservation by marketing and supporting energy-efficient house construction. In addition, utilities promoted the use of more efficient appliances, heating and cooling systems. By encouraging energy-efficient houses, electric utilities can reduce their loads and serve more residences with their available power and existing facilities.
Developers building today can construct energy-efficient homes that use fewer resources and cost less to operate. However, at some point they must still make the decision about what type of fuel they will use. After energy efficiency is addressed, then each space-and water-heating system variable (initial cost, unit life and life-cycle operating cost) can be evaluated. This will allow the developers and builders to select the best space- and water-heating systems for projects based on efficiency, cost, and environmental effects.
Recent research by the Environmental Protection Agency (EPA) has shown that existing home heating systems contribute more to the introduction of greenhouse gases in the U.S. than automobiles. Older house heating systems are only about 50%– 70% efficient in their burn cycle. So for every $1 of fossil fuel purchased only 50-70 cents of that dollar actually heats the house while the rest is lost up the flue. The 1993 Model Energy Code (MEC) in effect in many states today requires 80% minimum efficiency for new fossil fuel heating system installations. Heating systems with higher efficiency are available. Although their initial cost is more, they offer greater energy savings potential. The current life expectancy for a fossil fuel heating system is 20 to 25 years.
Most power plants use fossil fuels (e.g., coal, natural gas) to generate electricity. Electrical power is also generated by hydro-electric dams and nuclear power plants and, in a few areas, by wind or other renewable energy sources. Reducing the need for new power plants through demand reduction keeps the electric utilities' rates lower and also eliminates additional emission of greenhouse gases.
At the Pine Street Neighborhood, the design team had the option of electric or natural gas heating systems and water heaters. With both fuels readily available and neither showing a significant cost advantage, the developer opted to provide natural gas water heaters and to let the builder choose the heating fuel source. The architectural designs allow for either electric or natural gas heating systems. All designs specify the same insulation levels, energy-efficient windows and doors, air tightness criteria and energy recovery ventilators. Consumers will benefit by having properly-sized space-heating and water-heating systems that operate efficiently. So, no matter what heating fuel is chosen the house will be efficient, comfortable, quiet and have good indoor air quality.
Choosing an appropriate roofing material can be one of the greatest challenges of affordable, sustainable housing development. While there are a number of roofing materials with recycled content on the market, these tend to be considerably more expensive than a standard asphalt roofing. Reused or synthetic slate roofing materials offer some environmental benefits, but these premium products are seldom within the budget of affordable housing developments.
A number of composite and fiber-cement roofing materials are available; however, these also tend to be more expensive than asphalt shingles and some may not perform well in freeze/thaw climates. Since the climate of eastern Pennsylvania, where the Pine Street Revitalization is located, is definitely a freeze/ thaw area, fiber-cement roofing materials weren't seriously considered for the development.
Metal roofing is the most environmentally preferable choice in many cases, because it has recycled content, is again recyclable, and it is possible to combine rooftop water catchment systems for potable water with metal roofing. The price of metal roofing, however, is usually far above the cost of standard asphalt shingles, which significantly limits its application.
Most affordable housing developments end up using asphalt shingles. The main environmental drawback of these shingles is the inability to recycle them, combined with the relatively short life expectancy of the lower-end products— approximately 15 years.
Some lines of asphalt shingles do contain recycled material, which may consist of recycled paper and/or recycled industrial slag materials used as aggregate. Recycled content varies with manufacturers, brands and even colors. It may be difficult to obtain verification of recycled content in asphalt roofing shingles.
At the Pine Street development, the design team anticipated using asphalt shingleswith recycled content. They reasoned that saving a significant amount of money onroofing would make it possible to use environmentally preferable products elsewhere in the project. However, just as construction was about to begin, the Pine Street Revitalization project was awarded a $162,000 grant to support the purchase of recycled-content shingles. The grant came from a new grant program, the Pennsylvania Environmental and Energy Challenge (PEEC) grants, administered by the Pennsylvania Department of Environmental Protection. With this grant, the Pine Street development was able to choose a composite roofing product with high recycled content, a 50-year warranty and a slate-style appearance that contributed to the design aesthetic. The roofing slates made from recycled rubber and polymers help divert material from
Choosing an exterior cladding can be one of the most difficult design decisions in developing housing. Not only does the exterior finish play a significant role in the appearance of the house, but it can also be an important factor in the longevity of the structure. In an affordable, sustainable development, the challenge is to find an exterior cladding that optimizes cost, durability and environmental impact while providing aesthetic appeal.
Wood and wood-composite sidings are some of the most popular exterior cladding options. They can be cost-effective choices in some situations, and are often selected for their looks. However, most wood-based products are quite vulnerable to moisture, so their longevity may be compromised in wet or humid climates. To help protect them from the effects of weathering, almost all wood-based sidings require comparatively frequent maintenance in the form of paint or stain. This regular maintenance requirement is usually something that affordable housing developers seek to avoid, in order to spare future owners the expense and potential difficulty of frequent repainting.
In some areas of the country—notably the Northeast and North Central—vinyl siding, more formally polyvinyl chloride (PVC), has gained an increased residential market share in recent years, due in part to its low maintenance requirements. Because of its integral color, vinyl siding does not need to be painted, although some vinyl siding may "chalk" or fade as it ages. There are many different brands, styles and qualities of vinyl siding available, which differ radically in performance. Most sustainable building developers avoid use of vinyl siding, due to concerns about the environmental impacts of PVC manufacture and disposal.
Another exterior cladding option is fiber-cement siding. Fiber cement is a composite made from silica sand, cement binder and wood fiber reinforcement. The wood fiber is often recovered from industrial processes, though it comprises such a small proportion of the product that the siding as a whole cannot really be considered a recycled product. Fiber cement is a popular siding choice for its durability, embodied in its low coefficient of expansion, low rate of moisture absorption, and fire resistance. In many markets the purchase price of fiber cement siding is comparable to wood siding. Installing fiber cement siding requires that steps be taken to mitigate dust from cutting the material, such as using shears to cut the siding instead of saws. Although builders who haven't installed the product before may complain that they find the installation procedures burdensome, many builders across the country regularly install fiber cement siding successfully and without undue difficulty.
Fiber-cement siding is usually available pre-primed. Because of its dimensional stability, the material holds paint well. Fiber-cement cladding is available in shingle styles, lap siding styles and in panels.
At the Pine Street Neighborhood, the design team chose fiber-cement siding for the exterior cladding on the homes. According to area builders, fiber-cement siding is rarely used in the Hazleton market, so there was lengthy consideration on whether including it in the Pine Street development would discourage builders from bidding on the project, or raise prices. However, after careful research by the design team, fiber-cement siding stood out as the best cladding option for Pine Street when its performance benefits were weighed against its environmental cost. Furthermore, fiber-cement siding is manufactured within Pennsylvania, offering the efficiency and reduced transportation impact of a comparatively local product. Following consideration of all these factors, the design team decided that the Pine Street project would use fibercement siding as its exterior cladding.
In recent years, there has been an increase in scientific research and data suggesting that many homes, schools and office buildings have more polluted indoor air than most large industrial cities' outdoor air. Research also points out that we as a society spend more than 90% of our time indoors, putting our health at greater risk from indoor pollutants than from outdoor air.
People who are exposed to pollutants for longer periods of time can become more susceptible to their effects. People who spend more time indoors, and especially young children, the elderly and persons with chronic respiratory and cardiopulmonary disease, are at highest risk from prolonged exposure to pollutants in indoor air. These pollutants can include carbon monoxide, dust and other particulates, formaldehyde, radon, mold, pesticides and a variety of volatile organic compounds (VOCs), as well as a wide range of chemicals that may be irritants or allergens to particular individuals.
Even though individual pollutant sources may not pose a significant risk, most houses have more than one pollution source, and the cumulative effect causes concern. Informed homeowners can take steps to limit sources of existing pollutants in the home and avoid the introduction of new ones. The U.S. Environmental Protection Agency (EPA), along with the Consumer Product Safety Commission (CPSC), offers a free booklet to help homeowners reduce the levels of indoor air pollution in their homes. It's titled: The Inside Story: A Guide to Indoor Air Quality, available online at http://www.epa.gov/iaq/pubs/insidest.html or through the mail from EPA.
The primary cause of indoor air pollution is the release of gases or particles from sources within the house. Pollution sources can be either materials used in constructing and furnishing the home, or a result of occupant activities. Some examples include: combustion sources like gas, propane, kerosene, wood, oil, and tobacco products; building materials and household furnishings, finishes, carpets, and cabinetry; cleaning products; personal care items; hobbies; mold caused by excess moisture; introduction of outside air pollution or contaminants. Emissions of some pollutants are increased by high temperature and humidity levels. Central heating and air-conditioning systems can help spread pollutants throughout a building. Also, inadequate ventilation can contribute to poor indoor air quality by not providing enough fresh air to help dilute pollutants and exhaust stale air to the outdoors. In addition, poor ventilation can support the growth of molds and mildew by leaving moisture trapped inside the house.
Homes that are built to limit the amount of air that can enter them for energy-efficiency reasons can have indoor air quality problems. Yet many existing homes that have been weatherized or remodeled experience indoor air quality problems as well. Many households rely on natural ventilation and infiltration to change the air in the home. This means they rely on cracks and holes in the exterior walls or the opening of doors and windows to let fresh air in. But who leaves doors and windows open in the winter? Mechanical ventilation systems help ensure that houses have adequate air change rates, and promote improved indoor air quality.
Homes that are built with mechanical ventilation systems have the ability to exhaust pollutants and bring in fresh outdoor air on a regular basis. The systems may be as simple as properly sized and ducted bathroom fans or kitchen exhaust hoods programmed for a set amount of time each day. More complex ventilation systems include complete duct coverage and air-to-air heat exchangers that exhaust and supply air to various rooms in the home. These systems allow the homeowner to control the amount of ventilation air supplied and to exhaust pollutants out of the home. Many systems have timers that can be programmed to provide ventilation for a certain number of minutes every hour, throughout the day.
Some building materials and household furnishings emit pollutants primarily when they are first installed. Other products many continue to offgas over time. Activities such as painting or installing products with adhesives can leave high concentrations of pollutants in the air or trapped in carpets and furnishings for extended periods of time. To promote good indoor air quality, it's important to ventilate well, but it's also helpful to choose less-toxic and sealed materials and to specify installation practices that reduce pollution.
Building specifications for Pine Street Neighborhood call for low-VOC waterborne acrylic latex paint for interior walls and ceilings and low-VOC waterborne acrylic urethane finish sealers for interior doors, as well as wood flooring with a factory prefinished low-VOC waterborne finish. Additionally, kitchen cabinetry will be prefinished to seal all particle board surfaces to limit the outgassing of formaldehyde. Alternatively, the builder may opt to use formaldehyde-free particleboard, so that sealant doesn't have to be applied. By limiting the amount of "volatile organic compounds" (VOC) used in finishing the interior environment, as well as limiting the use of formaldehyde-containing products, the Pine Street design team has eliminated two common continuous emission sources. This will help occupants enjoy better indoor air quality in their new homes. Homes in the Pine Street Neighborhood will be equipped with mechanical ventilation systems in the form of properly-sized air-to-air heat exchangers that operate on timers. These systems will exhaust warm moist air from the kitchen, bathrooms and laundry room on demand and also regularly supply fresh air to the central living area and bedrooms. In addition, the homes will have kitchen exhaust hoods that are ducted to the exterior, in order to exhaust moisture and combustion by-products from gas ranges that builders may choose to install.
One of the most resource-efficient trim options Although trim pieces are generally relatively is to minimize the use of trim. By using a small, they are generally cut from technique called a "drywall wrap" window and comparatively large trees, because clear—knot-door openings can be
free—trim is the most desirable. Thus, reducing attractively finished the amount of clear, solid-wood trim used in a without the use of project can have a significant effect on the additional trim materials. One means of reducing the amount of clear though, unless the drywall wood trim used is to substitute a composite installers are quite trim, whether that be a paint-grade composite or proficient with the a wood composite with a finished-wood veneer. technique. Wood composites do contain adhesive, however, and one member of the design team for Pine Street felt strongly that wood composites should be avoided as part of the effort to promote good indoor air quality in the development.
For Pine Street, the design team considered several trim options. The drywall wrap technique was eliminated as an option because the target market was understood to perceive trim as a sign of value in construction. Oak trim was considered for the aesthetic it provided, and the design team researched the production of oak trim to assess the comparative impact of this wood species versus others. Finally, painted pine trim was selected for the project, as a relatively resource-efficient and cost-effective option.
Homes often get their roof design almost by default, not as a matter of conscious choice. The roof design may be a result of the architect's aesthetic sense, or the product of a desire to make a new home blend in with an existing neighborhood. What the developer may not realize, however, is that relatively slight changes in roof configuration and angle can make important differences in both project cost and sustainability potential.
A design with complex rooflines can add significantly to project cost, given the labor time devoted to installing multiple hips and valleys. This also raises potential for roof leakage, if those installations aren't absolutely correct. In addition, the homeowner will eventually pay a higher cost for replacement roofing on a complex roof.
A house roof can be a good location for renewable energy equipment, whether photovoltaic panels to generate electricity for the home, or a solar hot water system that supplies heated water for the household. Even if the development budget doesn't allow for the installation of solar systems now, orienting and angling the roof for their placement at a later date is a minor investment that leaves the opportunity for renewable energy wide open for future homeowners. The optimal roof design is one that provides a flat, unshaded roof surface oriented within 20 degrees of true South, and that offers an angle of 45 degrees.
While 45 degrees is a good angle for solar collection, it is not necessarily the best angle for an affordable home. Most roofers charge more for installing an especially steep roof, because of the extra fall protection that is required. Also, a steep pitch may require a larger amount of comparatively costly roofing material, without necessarily offering any more usable living space. On the other hand, nearly flat roofs have drawbacks, as well. Not only can they be prone to poor drainage and snow load buildup, but many roofing materials are not designed to be installed on low-pitch roofs, so the choice of available affordable roofing materials may be limited.
The design team and developer are challenged with adopting a roof design that is not only aesthetically appropriate, but also offers solar collection potential without increasing roof installation costs.
At the Pine Street site, it was impossible for all roofs to face within 20 degrees of South, since the small site and comparatively high density of housing restricted the orientation of homes on the site. However, the architect was careful to design the site plan so that each home had some solar potential. In order to preserve that solar access, restrictions were placed on future construction that would shade another homeowner's roof. The Pine Street homes will contain the plumbing for rooftop solar water heaters, a relatively low-cost investment at time of construction. The Pine Street Neighborhood will be constructed in several phases. The first phase of four houses will be equipped with one-kilowatt solar electric systems. These systems are expected to provide 20% to 30% of a typical natural gas-heated unit's electric needs. The systems are funded by utility universal system benefits funds available to low-income homeowners, the Low Income Renewable Energy Program and the Sustainable Energy Fund. All Pine Street units are solar ready and will readily accept solar hot water and solar electric systems in the future. Future homeowners will have the option of installing solar hot water or photovoltaics, as they desire, because the design team made the effort to incorporate proper orientation and workable roof angles in the original design.
ENERGY STAR is a national certification for be designed to meet ENERGY STAR standards. energy-efficient homes, commercial buildings, This would both establish an energy-efficiency appliances and equipment. Homes built to goal and provide a means for evaluating the ENERGY STAR standards typically use 30% less buildings' energy efficiency against energy than comparable homes built to comply independent standards. Computer simulation with the 1993 Model Energy Code. was done for each house design in the Pine
Street development, to model energy The developer of the Pine Street Neighborhood consumption and prove that the houses qualified was eager for the homes to be energy efficient. for the ENERGY STAR rating. The design team suggested that the development
Two of the design features that helped the Pine Street homes achieve the ENERGY STAR standard
Energy modeling is a proven way for the modeling available. Most comply with designer/architect/engineer to forecast the ASHRAE Standard 140-2001, which requires energy performance of proposed designs or to that energy modeling software be tested for determine what energy improvements will be accuracy and capability of handling any given most cost effective in retrofits. There are many building energy modeling problem. computer software programs for energy
|CURRENT STATE ENERGY CODE||ENERGY STAR|
|Energy Loss||% loss||Energy Loss||% loss|
|Above Grade Walls||R-11||21.7||23%||R-24||10.3||29%|
|Infiltration Measure||Blwr Dr||Blwr Dr|
|Gas Forced Air Furnace||80% EF||92.1% EF|
|Mechanical Ventilation||EX Only||2.8||3%||AAHX||0.5||1%|
|Annual Energy Cost Analysis|
|Energy Yearly Energy Costs||Base||Star|
|Lights & Appliances||$369||$369|
|Total Annual Energy||$1,176||$841|
Reusing salvaged building materials is one of the most resource-efficient strategies available to designers and developers. Reuse not only preserves the energy and resources invested in existing materials, but also alleviates the demand on remaining raw resources. This conserves resources, saves manufacturing and transport energy, and prevents waste.
Sometimes it's possible to reuse an entire building. Many success stories document cases where warehouses or other old industrial or commercial buildings have been converted to housing. This type of reuse is not always inexpensive, and may be a particular challenge for the developer as unforeseen problems with the existing building arise. Often the structural condition of the building and the extent of renovation needed to meet current codes don't become fully apparent until construction has actually begun. When structurally and economically feasible, whole-building renovations can provide distinctive, resource-efficient homes that help preserve community heritage.
For example, in instances where it's not possible to reuse a whole building, the developer may still have the option of reusing salvaged materials. Using salvaged materials in a new building project can produce financial and aesthetic rewards, though it also presents the design and construction team with some special challenges. For example, simply locating used materials can require extra time on the part of the design team. Coordinating procurement, storage and delivery of used materials are all important, but time-consuming, tasks. Because historic materials don't necessarily conform to today's standard building material dimensions, some design revision and field modifications may be required to accommodate particular products. Also, in multiple-unit construction projects, it may be difficult to secure enough salvaged materials to make all units match. Finally, it's important for the designer and developer to make sure that salvaged materials will meet applicable codes for structure, seismic performance, access and other provisions, and to make sure that salvaged materials aren't introducing hazards like lead paint or asbestos fiber into a new building.
For the developer who is willing to invest time and effort in obtaining and reusing salvaged materials, the rewards can be great. Some older materials are of a quality and craftsmanship not often seen today. They can lend an air of distinction to a home, a thoughtful detail that can be especially valuable in affordable housing. A number of affordable housing developers have successfully incorporated a wide range of salvaged materials in homes they have built.
One developer, Memphis Heritage, Inc., salvaged entire buildings when they led the renovation of ten shotgun and seven double-shotgun houses dating from the late 1920s and earlier. The renovation of these extremely dilapidated buildings helped preserve a vernacular style of housing that became popular in New Orleans around 1895 and spread throughout the South, but which is now vanishing. Rather than building new homes, the Delmar-Lema village project completely Meanwhile GreenHOME, an all-volunteer nonprofit organization dedicated to demonstrating and promoting affordable, sustainable design, construction and landscapes in the Washington, D.C., area, has used a number of salvaged materials in their new-home construction projects. Some of the materials that GreenHOME has salvaged and reused include heart pine flooring, wall studs, an antique brick foundation façade, walnut cabinets and a cast-iron bathtub.
In Missoula, Montana, affordable housing developer homeWORD has been able to reuse salvaged wood from existing dilapidated structures on building sites to construct privacy fences and as interior trim. In addition to including a renovated house within a new affordable housing development, homeWORD has also reused an existing commercial building, turning a historic hotel into affordable housing and retail space.
In addition to the examples above, some other materials that are good candidates for salvage and reuse include interior doors, glass block, brick, flooring, code-compliant fixtures and efficient windows. Even single-pane windows can be reused in applications that aren't thermally important, like transoms to light interior closets and room dividers. For developers willing to take the time and effort, the aesthetic, energy and resource benefits of materials reuse can be tremendous.
More than 90% of the homes built in the United States each year are wood framed. While dimensional lumber framing is the system that most designers and builders know best, some affordable housing developers are daring to push the envelope and build homes using alternative wall systems, such as structural insulated panels (SIPs) and straw-bale building.
Although SIPs, with a foam core sandwiched by sheathing, are typically thought of as an expensive type of construction, a PATH demonstration project documented their use in an affordable housing development. Carl Franklin Homes, a Texas builder, constructs affordable homes that feature structural insulated panel roofs and walls, as well as geothermal heating and cooling, tankless on-demand water heaters, and pigmented concrete floors. These features are included in homes priced around $85,000, which is far below the local average.
Several affordable housing developers have chosen to demonstrate a completely different construction technique, using stacked straw bales as wall structure and insulation. The thick bale walls offer good insulation, providing high R-value. Straw-bale construction has gained popularity in recent years, in part because the materials are comparatively cheap and can be installed using some unskilled labor. Some affordable housing developers have been able to assemble straw-bale walls quickly using large work parties of volunteers. While they may offer an attractive building technology for some, straw-bale homes often present challenges for developers, as well. Thick straw walls aren't well suited to the small lots of dense developments. Finding affordable interior and exterior finishes may be difficult, and accommodating trade contractors (i.e., electrical and cabinetry) with an unfamiliar wall system can lead to delays and added costs. In addition, unconventional straw-bale homes may be difficult for future owners and occupants to finance and insure, unless the developer assembles a purchase package for the buyer that covers these unusual homes.
Although straw-bale construction certainly isn't the answer for every affordable housing developer or every lot, it has helped some developers produce exemplary affordable and sustainable houses with walls built from local, rapidly-renewable resources.
Habitat for Humanity International affiliates and other affordable housing developers have constructed straw-bale homes in numerous locales, including: Spokane, Washington; Missoula, Montana; Minneapolis, Minnesota; and Pueblo, Colorado, as well as other communities scattered throughout the country.
At least one nonprofit housing developer has adopted straw-bale building wholeheartedly. Tierra Madre, an affordable housing developer working with low-income families in Sunland Park, New Mexico, is working with its residents to build a sustainable community with 47 straw-bale homes, community center, play area ,and alternative economic enterprise.
Depending on the number of houses in a development, and the efficiency of their design, other alternative wall systems may become cost-effective for affordable housing. Developers may want to consider various types of wall panels, as well as insulating concrete forms, as potential construction systems that offer enhanced energy efficiency and a shortened construction schedule.
Sometimes it is possible to reduce the cost of housing construction by eliminating redundant materials. For example, in designs where an exterior cladding that comes in 4'x 8' sheets is used, it may be possible to eliminate wall sheathing, rather than have the two panels adjacent to one another and performing the same function. Siding panels that consist of a finish on a panel of plywood substrate can assume the functional role of both sheathing and cladding. Similarly, stiff fiber-cement panels may also provide adequate shear strength, allowing sheathing to be eliminated.
The ability of panel cladding to stand in for sheathing depends on the strength characteristics of the particular cladding product, local code requirements, whether the building has multiple stories, and particular conditions to which the building may be subject. Even if it's only feasible to eliminate sheathing in certain areas of the building, this can still furnish both a material and labor savings for a building project.
When a development in Missoula, Montana, was designed and built with fiber cement panel cladding, the designer was able to eliminate supplemental sheathing from some of the walls in the 12-unit construction project. The fiber cement siding alone provided adequate strength and racking resistance.
Note that some builders may be reluctant to omit sheathing from the wall assembly because they are concerned about a perceived lack of wall stiffness. This can be adequately disproven using manufacturer material on siding characteristics and performance. Eliminating sheathing on only some wall areas requires careful attention to detail, since it changes the dimensions of the wall and may require furring or adjustment of window and door openings and trim. When the builder is aware of the plan to omit sheathing and can plan for the process from the beginning of construction, it shouldn't pose added difficulties, and should actually help shorten construction time.
It may be of interest to note that at least one metal panel roofing manufacturer makes a stiff panel with integral purlins that allows the elimination of roof sheathing. Here again, a panel product can offer substantial labor and material cost savings, provided the available roofing style meshes with the project's requirements.
Eliminating unnecessary duplication of structural systems is a great way to make a project more resource-efficient, as well as more cost-efficient.