What is green building?
Since the early 1990’s the terms “green” and “sustainable” have been used interchangeably and quite extensively when describing a certain approach to building. Wikipedia defines sustainability for humans “…as the potential for long-term maintenance of well-being, which has environmental, economic, and social dimensions, and encompasses the concept of stewardship, the responsible planning and management of resources.” Green, as it applies to housing, has come to refer to the emphasis on minimizing the environmental impact of the initial building construction and improving the quality of life and comfort of the building occupants. The term ‘green’, however has become so overused and people’s understanding of the meaning is often so limited that it has become difficult to make informed decisions about green building. The term that I think more accurately describes this approach to building is ‘high performance building’ and in this article I will describe a fairly simply way of understanding high performance building.
The environmental impact of the initial building construction translate simply into careful attention being paid, during design and construction, to what is known as the three R’s: reduce, reuse and recycle. The first of these: reduce, is easily applied to remodeling as well as new home construction during the design phase by creating a design that reduces the use of materials and the production of waste. The easiest way to do this when remodeling, if more usable space is desired in an existing home, is by reconfiguring inefficient or underutilized rooms or hallways in the house instead of adding on more floor area. It is amazing how comfortable and useful a smaller space can be when it is efficiently and creatively designed. When designing and building a new home, careful and thoughtful design that results in home that is only as large as is necessary to meet the needs of its occupants is the easiest way to build green. Also, during the design phase of a project, eliminate waste by paying attention to floor, wall and ceiling dimensions so that standard size materials can easily be used.
The second “R”, reuse, can be achieved by careful demolition and reuse of existing materials in a remodel. Sometimes useful materials are salvaged during a remodel and for some reason can’t be used in the newly remodeled space. They don’t have to be discarded and added to the landfill but instead can be recycled by donating them to one of the local recycling yards, such as ReStore, run by Habitat for Humanity in Santa Rosa.
The third “R”, recycle, can be achieved by building with materials salvaged from other buildings or if new materials are used, by using materials made with a high recycled content. Examples that are readily available and commonly used are framing and sheeting materials that have replaced dimensional lumber and are made from wood chips and waste from milling operations, decking and flooring products made from recycled plastics, insulation made from recycled paper or cotton, countertops made from recycled paper or glass, concrete made with fly-ash, a by-product of coal burning power plants, as a substitute for cement, and many more.
The other criteria for evaluating improvements to your home have to do with improving the quality of life and comfort of the building occupants. While the three R’s apply to your building’s impact on the environment, this has more to do with the personal side of green building: increased durability of your home, improved quality of the air you breathe in your house, increased comfort inside your home free from drafts or from rooms that are too hot or too cold and lower utility bills. The interesting thing about these items is that they are all part of the same system. A change to one will have an effect on all of the others.
High performance building focuses first, whenever possible, on the building shell. This is where there is the greatest opportunity to improve all parts of the building system. Improving the insulation and air sealing all exterior surfaces of a building reduces the infiltration of dirty, humid air into your home, improving the indoor air quality. It also reduces the leakage of heated or cooled air from inside your home, reducing the energy usage, improving comfort and extending the life of the mechanical equipment. In addition, it reduces the transmission of moisture from outside the house into the structure, thereby extending the life of the building. There may be an adverse effect, however, on another part of the system by improving the integrity of the building shell. The well sealed and well insulated building is now less able to dilute any chemicals off gassed from new building materials used in the construction. Careful attention must be paid to be sure they are free from the volatile organic compounds found in many paints, flooring products, cabinets and other man made products in order to avoid a degradation in the indoor air quality.
Another common misunderstanding about green building is that the installation of a photovoltaic solar energy system alone will improve energy efficiency. The fact is that unless improvements are made to the building shell, or the furnace and appliances are replaced with more efficient ones or the lighting is replaced with high efficacy fixtures or bulbs, there will be no improvement in energy efficiency. A PV solar system is a great way to harness free energy from the sun, but when it is installed without careful consideration of the other components of the building’s system, all it is doing is lowering the monthly utility bills. It is not conserving energy, and it is not very green.
If your goal is to “go green” then ignore the claims made by salespeople, marketers and manufacturers about how ‘green’ a product is and instead ask the following two questions:
Does it achieve one or more of the three R’s?
Does the proposed construction result in an improvement to the building’s durability, comfort, indoor air quality or energy efficiency without reducing the quality of any of the others?