by Jon Gunson, Architect
Green has become an often-used buzzword to describe a genuine concern and ethic toward our environment. In relation to residential construction, it indicates awareness about the materials that go into a home, the way the home is built, the amount of energy used to manufacture and deliver the products that are within the home, and the energy it will consume while you are living in it.
Buildings are responsible for 54% of the nation’s energy consumption and 35% of our carbon dioxide emissions through their construction and operation of heating and cooling systems and maintenance. Therefore, buildings present one of the world’s best opportunities for eco-friendly design and energy savings.
Because mountain construction is in a heating climate, energy conservation is the quickest, cleanest, and cheapest way to lessen our impact on the environment. It also has the added bonus of saving you money on your utility bills. There are 4 components that contribute to conserving energy on your home: Design, materials, energy efficiency, and your lifestyle.
- Design – The basic concept of an energy conscious design is to allow the sun into your home when it is desired (winter) and keep it out of your home when it is not wanted (summer). The ideal way of doing this is to angle the main axis of your home within 30 degrees east or west of true south. This gives you the largest sun exposure to your roof slopes and windows. With this principal in mind, windows should ideally be located on the south side of the home; secondarily on the east and west side and, if possible, avoid windows on the north side of the home.
In addition to orientation and window placement, the third component of energy conscious design is to calculate the seasonal sun angles for the location and orientation of your house. With this information, your Architect can provide the correct length of the roof eaves to shade your windows in the summer and still allow sunlight to enter your home in the winter when the sun is lower in the sky.
With the proper orientation of windows and outdoor spaces, you can gather free energy from the sun and also shield your home from winter winds. Decks and patios can be located to be sheltered from the wind. Longer roof overhangs can also protect these areas from rain and snow which will extend your use of outdoor spaces.
- Materials – Today’s homes are often composed of hundreds of different products from all over the world. A more “green” approach is to try to select materials that are produced as close as possible to your home site, which will reduce pollution related to transportation. It will also insure that you are not purchasing materials which are produced in countries with no environmental protection laws. Secondly, you can look for products made from recycled or renewable materials. These products usually take less energy to produce and consume less of our natural resources. The third consideration in product selection is low toxicity. Try to choose products that not only contain non-toxic materials, but also those that do not use toxic materials in the production process. Finally, look for products that are durable. Materials that last longer and need less maintenance will reduce the energy required for repair or replacement.
All of these considerations in selection of materials will help reduce our overall impact on the environment, however, the most important choice of materials you can make to “build green” is your selection of insulating products.
The greatest loss of energy from your home is through the outer shell. Therefore, your biggest payback to the environment and your checkbook is investing in better insulation values for your roof, walls, and windows. R-value is the measure of resistance to heat flow. The higher the R-value, the more resistance and the more savings in cost from energy loss. By far, the greatest advance in insulation for your roof and walls is sprayed polyurethane foam. This is the same insulation that keeps the cold inside your refrigerator and it will work just as well to keep the cold outside of your home. With polyurethane, your roof can be insulated up to R-50 and your exterior walls to R-25. In addition to being a great insulator, it is amazingly effective at blocking out the wind by sealing up all of the tiny cracks and holes which are all around the outer envelope of your home.
The other critical components of an energy efficient home are well insulated windows and doors. Most mountain homes feature large windows to welcome the views and beautiful surroundings. However, the average home may lose up to 30% of its energy through poorly insulated windows. A single layer of glass has an insulating value of only R-1 so installing an R-1 window in an R-25 wall is almost the same as having holes in the sides of your home. But window manufacturers are constantly working to improve their insulating capabilities. More layers of glass, with an air space between them, will provide more resistance to heat flow and therefore higher R-values. R-values can be improved still further by filling the space with an inert gas instead of air. In addition, the surfaces of the glass can be covered with a transparent coating, which acts like an invisible mirror, reflecting heat back toward the warm side of the glass. For a nominal cost, these treatments can boost the insulating value of a window to R-4. With a larger investment, for more layers and coatings, you can purchase windows with insulation up to R-7.
- Energy Efficiency – With all of the modern conveniences and the latest technology that is available in today’s homes, it is easy to overlook all of the energy consumed just by operating our appliances, electronics, lighting, and heating and cooling equipment. But, worldwide, using your energy in an efficient way is the cheapest, quickest, and cleanest way to conserve the Earth’s energy resources and reduce pollution. This means carefully selecting products for your home that consume less energy during operation and no energy when shut off or in stand-by mode. Also, just like added insulation, another enormous bonus of selecting these products is that they will save on your utility bills.
The U.S. Department of Energy has made it easy for us to select these energy saving products by requiring manufacturers to give us accurate information about how much energy they consume. Their “Energy Star” program identifies products that have met the D.O.E. guidelines for efficiency, and they are even required to show you information on the projected annual savings you will have by using them.
However, going beyond the “Energy Star” ratings, the ultimate products for energy efficiency are those that actually produce energy rather than consume it. These products can be grouped into two categories: those that produce electricity and those that produce heat.
To produce electricity for lighting and operating appliances and electronics, the best choices are to convert energy from the sun or from the wind. If you have a sunny site, you can install photovoltaic panels on the south side of your roof. These panels absorb the sun’s energy and convert it into electricity. With enough panels, you may be able to produce electricity to supply your entire house. Other benefits are provided by some of the government and utility company programs that will subsidize installation costs and also, in some areas will even buy back any excess electricity your system produces.
Another way to produce energy from a non-polluting source is to convert the forces of the wind into electricity. A simple description of this is in using the wind to rotate the blades of an old-fashioned windmill, but instead of grinding grain or pumping water, the rotating blades turn a turbine which produces electricity. Another comparison is to think of an electric fan which uses electricity to rotate the fan blades to blow out air and cool you. Now, think of this system running in reverse: Natural wind blows against the fan blades causing them to rotate. They turn the electric motor in reverse, producing electricity and pushing it back into the wires to light up your home. This is an excellent system for locations which have relatively constant winds, such as coastal areas which often have more wind and less solar access. The air flow is usually less turbulent higher above the Earth’s surface where it is not blocked by trees and buildings. For this reason, a wind turbine should be elevated at least 50 feet off the ground. It must also be able to rotate in order to face directly into the wind.
These are two good sources for producing electricity for lighting and small appliances, but electrical energy is not an efficient way to heat your home or even to heat water for washing and bathing. For heating, there are three energy conscious choices. The first is the age-old method of burning wood. However, this heat source only fits the “green” test with two qualifiers. First, you need a supply of fuel that would otherwise be wasted, such as dead trees or by-products from other sources. The other qualifier for burning wood is to use a clean-burning, energy efficient stove. This type of stove meets the EPA requirements to avoid air pollution.
A second choice for heating is, again, collecting the sun’s energy, but this time with hydronic solar panels that concentrate the sun’s energy to heat water and then pump it through rows of plastic tubing which are laid just below the surface of your floor. The heat rises upward, producing warm radiant floors throughout your home, which is ideal for mountain living.
The third type of energy efficient heating is called “geothermal” because it utilizes heat from the earth rather than the sun. The temperature of the earth at 10 to 20 feet below the surface stays almost the same year-round. Coils of tubing are installed in wells or deep trenches and water is circulated through them to extract this heat from the ground. Then a “heat pump” concentrates this heat to raise the temperature so that it can circulate through the same type of radiant floor heating system just previously described.
- Lifestyle – Up to this point we have discussed three of the four “green” components to utilize in your home: Design, Materials, and Energy Efficiency. These previous three components have dealt with physical things such as methods, products, and equipment that you can utilize to help make your home more energy efficient. The fourth component focuses the responsibility on you and your family to conserve energy every day through the way you live. This means to consume less, re-use more, and recycle as much as possible. On a personal level, each of us can change our attitude and easily consume less energy by turning down the thermostat, turning off unused lights, combining auto trips, and dozens of other similar actions in our daily routines.
Another part of our change in attitude to living “green” is to re-use as many things as possible instead of discarding them. This includes everything from grocery bags and food containers to clothing and even automobiles.
Even if you decide you can’t re-use something, you can very likely recycle it. 90% of the products we use, or the containers for them, are glass, plastic, metal, or paper, and all of these materials have become easy for us to recycle through many local programs and collection sites.
Finally, consider working with an Architect who is L.E.E.D. (Leadership in Energy and Environmental Design) Certified. A good Architect can design your home to incorporate all of the aspects of “Green Construction” in order to use our resources wisely, conserve energy, re-use materials, and recycle heat or cold to maintain a comfortable home. The way you live and the home you live in represent tremendous opportunities for innovative, eco-friendly design as well as cost savings.
Filed under: Articles by Jon Gunson
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