LEED for Homes Point Categories

The LEED for Homes voluntary rating system awards certification based on point totals in eight categories. (Download the checklist for point requirements.) The categories and requirements are developed through a rigorous consensus-based process, including a period of USGBC member balloting.

Innovation & Design Process
Location & Linkages
Sustainable Sites
Water Efficiency
Energy & Atmosphere
Materials and Resources
Indoor Environmental Quality
Awareness & Education

Innovation & Design Process
Sustainable design strategies and measures are constantly evolving and improving. New technologies are continually introduced to the marketplace, and up-to-date scientific research influences building design strategies. Occasionally, a strategy results in building performance that greatly exceeds that required in an existing LEED credit. Other strategies may not be addressed by any LEED prerequisite or credit but warrant consideration for their sustainability benefits.

Green home-building strategies and techniques are most effectively implemented as part of an integrated design process, with input from individuals involved in each phase of the project. Good design can keep costs down and ensure proper integration of green techniques and achievement of project goals.

One aspect of home design that is often overlooked is the assessment and mitigation of long-term durability risks to the home. Durability failures are a significant cost and cause of stress for both builders and homeowners, but many easy and low-cost strategies are often overlooked because builders do not consider durability in the up-front design.

The Innovation & Design Process (ID) credit category encourages project planning and design to improve the coordination and integration of the various elements in a green home.

Credits can be earned for innovative designs, exemplary performance or regional best-practices that can be shown to produce quantifiable environmental and human health benefits.

The three Innovation & Design Process credits in the LEED for Homes Rating System are:

Integrated Project Planning
Durability Management Process
Innovative or Regional Design.


Location & Linkages
Home-building projects have substantial site-related environmental effects, in terms of both the impact to the site itself and the impacts that stem from the location of the site. The Sustainable Sites credit category focuses on the former; Location & Linkages addresses how builders can choose site locations that promote environmentally responsible land-use patterns and neighborhoods.

Location & Linkages (LL) credits reward builders for selecting home sites that have more sustainable land-use patterns and offer advantages over conventional developments. Land is used more efficiently, reducing the acreage needed for new housing. Fragmentation of farmland and forest and other natural areas is minimized. Well-sited developments need less infrastructure, especially roads and water and sewer lines. And such developments promote a range of sustainable transportation options, including walking, cycling and mass transit, thereby reducing dependence on personal automobiles.

LL credits can be earned in either of two ways:

Pathway 1: LL 1, LEED for Neighborhood Development.
The LEED for Neighborhood Development program certifies “smart-growth” housing development. The pilot phase of this program is expected to conclude in late 2008, after which new projects can register and receive credit for selecting a home site in a certified development.

Pathway 2: LL 2–6.
Projects that either cannot or choose not to participate in the LEED for Neighborhood Development program can earn points in this category by pursuing the following strategies:

LL 2: Site Selection
LL 3: Preferred Locations
LL 4: Infrastructure
LL 5: Community Resources
LL 6: Access to Open Space


Sustainable Sites
Green building goes beyond the built structures because the use of the site and its natural elements can have a significant environmental impact. The Location & Linkages category awards projects for choosing a preferable site; the Sustainable Sites category awards projects for minimizing site impacts.

Early decisions about how to incorporate the home into the site can have significant long-term effects on local and regional ecosystems, as well as demand for water, chemicals and pesticides for site management. Good design decisions can result in attractive, easy-to-maintain landscaping that protects native plant and animal species and contributes to the health of local and regional habitats.

Depending on how a home is integrated into the site, normal rainfall can be a problem, causing soil erosion and run-off of chemicals and pesticides or an opportunity to offset potable water demand and recharge underground aquifers. Surrounding plants can be a burden, requiring regular upkeep, watering and chemicals, or an enhancement that provides shade, aesthetic value, habitat for native species and a mechanism for absorbing carbon and enriching the soil.

Site design should take into consideration the aesthetic and functional preferences of the occupants, but also long-term management needs, preservation principles and potential impacts on local and regional ecosystems.

The six Sustainable Sites (SS) credits in the LEED for Homes Rating System:

Site Stewardship
Landscaping
Local Heat Island Effects
Surface Water Management
Non-toxic Pest Control
Compact Development


Water Efficiency
In the United States, approximately 340 billion gallons of fresh water is withdrawn per day from rivers and reservoirs to support residential, commercial, industrial, agricultural and recreational activities. This accounts for about one-fourth of the nation’s total supply of renewable fresh water. Almost 65 percent of this water is discharged to rivers, streams and other water bodies after use and, in some cases, treatment.

Additionally, water is withdrawn from underground aquifers. In some parts of the United States, water levels in these aquifers have dropped more than 100 feet since the 1940s.

On an annual basis, the water deficit in the United States is currently estimated at about 3,700 billion gallons. In other words, Americans extract 3,700 billion gallons per year more than they return to the natural water system to recharge aquifers and other water sources.

Water for domestic use may be delivered from a public supplier or be self-supplied isby a well. Self-supplied domestic withdrawals are an estimated 3,590 million gallons per day.

The Energy Policy Act of 1992 mandated the use of water-conserving plumbing fixtures and fittings to reduce water use in residential, commercial and institutional buildings. Water efficiency measures in new homes can easily reduce water usage by 30% or more. In a typical home, savings of 30,000 gallons of water a year can be achieved very cost-effectively. This results in average annual water utility savings of about $100 per year.

As communities grow, increased demand for water leads to additional maintenance and higher costs for municipal supply and treatment facilities. New homes that use water efficiently have lower water use fees and reduced sewage volumes. Many water conservation strategies involve either no additional cost or rapid paybacks; biological wastewater treatment, rainwater harvesting and gray water plumbing systems, on the other hand, often involve more substantial investment.

The Water Efficiency (WE) category in the LEED for Homes Rating System has three kinds of credits:

Water Reuse
Irrigation Systems
Indoor Water Use

Energy & Atmosphere
Data from the home-building industry indicate that close to 1.5 million new homes are built each year, and that the average size of new homes has doubled in the past 50 years. As a result, total U.S. fossil energy use in homes has been steadily increasing. The average American consumes five times more energy than the average global citizen, 10 times more than the average Chinese person, and nearly 20 times more than the average Indian.

Conventional fossil-based generation of electricity releases carbon dioxide, which contributes to global climate change. Coal-fired electric utilities emit almost one-third of the country’s anthropogenic nitrogen oxides, the precursor of smog, and two-thirds the sulfur dioxide, which causes acid rain. They also emit more fine particulate material than any other activity in the United States. Because the human body is incapable of clearing fine particles from the lungs, these emissions are contributing factors in tens of thousands of cancer and respiratory illness-related deaths annually. Natural gas, nuclear fission and hydroelectric generators all have adverse environmental impacts as well. Natural gas is a major source of nitrogen oxides and greenhouse gas emissions. Nuclear power increases the potential for catastrophic accidents and raises significant waste transportation and disposal issues. Hydroelectric generating plants disrupt natural water flows, resulting in disturbance of habitat and depletion of fish populations.
Buildings consume approximately 37% of the energy and 68% of the electricity produced in the United States annually, according to the U.S. Department of Energy. In 2006, total emissions from residential buildings were responsible for 1.2 billion metric tons of carbon dioxide (CO2) emissions, or 20% of the U.S. total.

Scientists predict that left unchecked, emissions of CO2 and other greenhouse gases from human activities will raise global temperatures by 2.5ºF to 10ºF over the 21st century. The effects will be profound and may include rising sea levels, more frequent floods and droughts and increased spread of infectious diseases. To address the threat of climate change, greenhouse gas emissions must be slowed, stopped and reversed. Meeting the challenge will require dramatic advances in technologies and a shift in how the world economy generates and uses energy.

Absent significant improvements in environmental performance, the residential building sector will be a major contributor of global CO2 emissions. Homes have a lifespan of 50 to 100 years, during which they continually consume energy and produce CO2 emissions. Further, the U.S. population and economy are projected to grow significantly over the coming decades, increasing the need for new homes. To meet this demand, approximately 12 million new homes are projected to be constructed by 2015.

Building green homes is one of the best strategies for meeting the challenge of climate change because the technology to make substantial reductions in energy and CO2 emissions already exists. The average certified LEED home uses 30% to 40% less electricity and saves more than 100 metric tons of CO2 emissions over its lifetime. Modest investments in energy-saving and other climate-friendly technologies can yield homes and communities that are healthier, more comfortable, more durable, energy efficient and environmentally responsible places to live.


Materials & Resources
The choice of building materials is important for sustainable homebuilding because of the extensive network of extraction, processing and transportation they require. Activities to produce building materials may pollute the air and water, destroy natural habitats and deplete natural resources. Construction and demolition wastes constitute about 40% of the total solid waste stream in the United States. Good design decisions, particularly in the framing of homes, can significantly reduce demand for framing materials, as well as the associated waste and embedded energy. Without even changing the home design, a project can save framing materials and reduce site waste by planning appropriately and communicating the design to the framing team through detailed framing documents and/or scopes of work.

Sources should be evaluated when materials are selected for a project. Reclaimed (i.e., salvaged post-consumer) materials can be substituted for new materials, saving costs and reducing resource use. Recycled-content materials reuse waste products that would otherwise be deposited in landfills. Use of local materials supports the local economy and reduces the harmful impacts of long-distance transport. Use of third-party-certified wood promotes good stewardship of forests and related ecosystems. Use of low-emitting materials will improve the indoor air quality in the home and reduce demand for materials with added volatile, toxic compounds.An increasing number of public and private waste management operations have reduced construction debris volumes by recycling these materials. Recovery activities typically begin at the job site, with separation into multiple bins or disposal areas. In some areas, regional recycling facilities accept commingled waste and separate the recyclable materials from those that must go to the landfill. These facilities can achieve waste diversion rates of 80% or greater.

The Materials & Resources (MR) category in the LEED for Homes Rating System has three components:

Material-Efficient Framing
Environmentally Preferable Products
Waste Management



Indoor Environmental Quality
Americans spend on average 90% of their time indoors, where levels of pollutants may run two to five times — and occasionally more than 100 times — higher than outdoors, according to the U.S. Environmental Protection Agency. Similarly, the World Health Organization reported in its Air Quality Guidelines for Europe that most of an individual's exposure to many air pollutants comes through inhalation of indoor air. Many of the pollutants found indoors can cause health reactions in the estimated 17 million Americans who suffer from asthma and 40 million who have allergies, contributing to millions of days absent from school and work.

Homeowners are just beginning to realize the link between their health and their homes. Hazardous household pollutants may include carbon monoxide, radon, formaldehyde, mold, dirt and dust, pet dander, and residue from tobacco smoke and candles. Many homeowners also store various chemicals inside their homes as well, including pesticides, fertilizers, solvents, grease, oils, degreasers, gasoline, antifreeze, strong detergents, thinners and oil-based paints.
Over the past 20 years, research and experience have improved our understanding of what is involved in attaining high indoor environmental quality and revealed manufacturing and construction practices that can prevent problems from arising. Preventing indoor air quality problems is generally much less expensive than identifying and solving them after they occur. Generally, there are three types of strategies: source removal, source control and dilution.

Source removal is the most practical way to ensure that harmful chemical compounds are not brought into the home. Evaluating the properties of adhesives, paints, carpets, composite wood products and furniture and selecting materials with low levels of potentially irritating off-gassing can reduce occupant exposure. Scheduling deliveries and sequencing construction activities can reduce exposure of materials to moisture and absorption of off-gassed contaminants. (Low-emissions materials are addressed under Materials & Resources.)

Source control strategies focus on capturing pollutants that are known to exist in a home. For example, filtering the supply air stream removes particulates that would otherwise be continuously recirculated through the home. Protection of air-handling systems during construction and a building flushout prior to occupancy further reduce the potential for problems.

Dilution involves the use of fresh outside air to ventilate a home and exhaust pollutants to the outdoors. This may also help control moisture within the home. Most new homes in the United States do not have mechanical fresh-air ventilation systems. The typical air-handling systems in new homes merely recirculate the air within the home, continuously pumping indoor pollutants through the home rather than exhausting them.

Another aspect of indoor air quality is occupant comfort. The proper installation of automatic sensors and controls to maintain proper temperature, humidity and ventilation in occupied spaces helps maintain optimal air quality. Surprisingly, sensors to alert a home’s occupants to deadly carbon monoxide concentrations are frequently not required by current codes but should be included in all new homes. Letting occupants fully and effectively control their thermal environment can reduce hot-cold complaint calls and generally raise satisfaction levels.

The Indoor Environmental Quality (EQ) credit category encourages builders to prevent air pollution and improve air quality and comfort in the homes they build.

Alternative Compliance PathwaysThe two parallel pathways through the 10 EQ credits in the LEED for Homes Rating System are illustrated in Table 1 and summarized below.

Pathway 1: ENERGY STAR with Indoor Air Package

Projects that participate in the U.S. Environmental Protection Agency’s ENERGY STAR with Indoor Air Package initiative automatically qualify for 13 points. Up to 7 additional points are available if the following credits are also completed:

EQ 4.2: Enhanced Outdoor Air Ventilation
EQ 5.2: Enhanced Local Exhaust
EQ 5.3: Third-Party Testing
EQ 7.2 or 7.3: Better or Best Air Filters
EQ 8.2: Indoor Contaminant Control

Pathway 2: Prescriptive Approach

The following strategies can earn points in this credit category:

EQ 2: Combustion Venting
EQ 3: Moisture Control
EQ 4: Outdoor Air Ventilation
EQ 5: Local Exhaust
EQ 6: Distribution Systems
EQ 7: Air Filtering
EQ 8: Contaminant Control
EQ 9: Radon Protection
EQ 10: Garage Pollutant Protection


Awareness & Education
The LEED for Homes Rating System addresses the design and construction of new green homes — roles that are the responsibility of the home designer and the builder, respectively. But the environmental impact of a home continues throughout its life-cycle, well beyond the initial design and construction decisions. Most new homes are expected to last 50 to 100 years, during which the occupants will consume energy, water and other resources. They therefore play a substantial role in the resource use of a home over its lifetime.

Some homebuyers may know very little about green home construction. They may be unaware of the green features in the home, or they may be unfamiliar with how to use and maintain them. Without adequate training, the full benefits of the LEED measures likely will not be achieved.

This credit category promotes broad awareness among homebuyers and tenants that LEED homes are built differently and need to be operated and maintained accordingly. Because the operations and maintenance tasks in multifamily buildings may be performed by a building manager, this credit also addresses the need for appropriate education of building managers.

The two Awareness & Education (AE) categories in the LEED for Homes Rating System are Education of the Homeowner or Tenant and Education of the Building Manager.