Green Building
Frequently Asked Questions

What is a Green building?

"A green building is one where the qualities of both the indoor and outdoor environments have been considered and protected during its design, construction, maintenance and use."

What are some of basic tenets of a built green home?

Built green homes

  • Have improved energy efficiency
  • Conserve water
  • Have improved indoor air quality
  • Are more durable and more comfortable, and
  • Reduce pollution and save natural resources

Another basic principle of green building is to build as little as necessary. Not only does new construction demand more resources, it can also contribute to urban sprawl. Green building encourages home purchases of existing structures which are convenient to public transportation, work, shopping, and other services. It also encourages expansion of an existing home rather than building a new home and downsizing new construction.

Why downsize new construction?

A smaller house uses fewer materials and costs less to construct, is easier and more economical to maintain and heat, and typically leaves more yard space outside to enjoy. Designs should use less material and create less waste. Material and disposal costs can be reduced by including waste reduction specifications and plans.

Examples of this include using standard sizes of lumber, centralizing cutting operations, safely increasing the spacing of joists and studs, and carefully calculating the quantities of materials needed at the outset of projects.

Specifications that call for environmentally preferable materials and construction practices can be added to a remodeling or home construction contract.

Why buy locally produced building materials?

Buying regional products reduces transportation costs and energy, and keeps dollars in the local economy. A major tenet of sustainability is making use of resources from the immediate region. Local hardwoods, for example, are preferable to tropical woods.

What part do reused and recycled building materials play in green building?

Purchasing materials that contain recycled content helps to support recycling efforts in the community, state, region, and nation. These products also reduce solid waste problems, cut energy consumption in manufacturing, and save natural resources. Some examples include materials with recycle content include cellulose insulation, Homosote, Thermo-ply, floor tile made from ground glass, and recycled plastic lumber. Salvaged building materials which are incorporated should be safe (test for lead paint and asbestos) and should not sacrifice energy or water efficiency.

What about:

Plastic lumber?

A number of recycled-content deck products are currently on the market. These products offer low maintenance, durability and an attractive option to cedar or redwood decking without the same periodic maintenance requirements for long lasting performance. These products are made either entirely or partially from recycled plastic, which helps close the recycling loop by finding useful end products for recycled material.

Cement – fiber siding and other siding alternatives?

Cement-fiber is made of a mixture of cement and some type of fiber. Cement – fiber siding is very durable, does not split, holds paint longer and is more moisture –resistant than typical hardwood siding. Other options include recycled content hardboard, stucco and locally produced brick and stone.

High performance windows?

Windows, more than any other standard building item, have seen a significant increase in performance resulting from new technologies such as "low-E" glass coatings and gas-filled windows. These improvements make higher costs palatable, or even economic, when the rest of the home’s heating system is adjusted accordingly.

If the windows are a part of an overall energy strategy that greatly reduces the demand on the heating system, the savings gained in going to a smaller furnace can offset the added cost of the windows, and the on-going energy savings will pay back that extra cost more quickly. However, the most frequent selling point for these high-performance windows is the added comfort over a standard window.

VOCs and Indoor Air Quality?

VOCs are Volatile Organic Compounds. VOCs can be released by human or natural source, and can react with the atmosphere to form ground-level ozone, and to a lesser degree, acid rain. Some VOCs, like the fumes from numerous interior products (glues, paints, cabinets, carpets, and pads, furniture, etc.) are toxic, and can cause a range of health problems from occasional headaches to allergic reactions, depending on the concentration and the sensitivity of the individual. "Least toxic" products are those which contain levels of VOCs below what the EPA or other credible sources have determined to be safe levels. In some cases, a "least toxic" product may be preferable to a "non-toxic" product for reasonable performance. For additional assurance, consider mechanical ventilation with an air-to-air heat exchanger that gives fresh air without wasting heat.

Carpet made from soda bottles?

Carpet made from fibers spun from recycled plastic soda bottles is now commonly available. This carpet performs as good or better than carpet made from other materials, and costs less than most. The advantages include excellent stain resistance and durability. This carpet is a useful product made from material often thrown in the landfill. 500 square yards of carpet divert about 20,000 soda bottles from landfills. Carpet padding made from recycled fibers reduces the need for petrochemicals and outgasses less than a typical foam pad.

Leaky ducts?

Duct systems can be leaky in many areas and most are. Studies have shown that a typical duct system leaks from 20% to 40% of the heated air that should be getting to the various rooms of the house. This is bad for energy bills and worse for health and safety. A leaky duct system can create pressure differences in a home’s heating system which can draw in contaminants like dust from the attic, soil gasses, or flue gasses. A well-designed, well sealed duct system should be a fundamental part of an energy-efficient home. The duct system should be sealed at all joints and penetrations with brush-on, low/non toxic mastic, not duct tape.


A well designed yard needs less water and maintenance, and saves money. Native vegetation competes well with weeds and other pests. Emphasize plant diversity by grouping plants which naturally grow together and are self-sustaining (i.e. self-seeding and spreading without much maintenance) As a result, less fertilizer and pest control is required. Using native, indigenous plants will reduce the need for water. Since native plants may be already accustomed to the climate, they are drought resistant and withstand greater climate variations than non-native plants.

Landscape designs should avoid incorporating allergy-causing plantings and those requiring chemical treatment adjacent to air intakes, entries, or operable windows.

Landscape designs can help reduce energy bills. Placing a windscreen of evergreens on the northwest side of a house will block winter winds. Locating an air conditioner on the north side of the house and shading it with a tree will keep it cool in the summer and reduce energy use. Planting large shade trees on the east and west sides of a house will shade the summer sun and keep a house cooler.

Additional Sources of Information

The Environmental Building News
Oikos/Green Construction Source
CT Green Building Council
U.S. Green Building Council
Building Online
American Water Works Association
U.S. Department of Energy 
The Green Building Source Book
High Performance Building Guidelines NYC Department of Design & Construction
Construction & Demolition Materials Management

This information is provided as a service to those professionals in the construction industry. This information does not include all available references and does not constitute an endorsement by DEEP. Use of this information does not in any way lessen your responsibilities for compliance with applicable federal, state, and local laws.

Green Building

Content Last Updated February 2020