Most Important Resource in Building Green Is Common Sense

By Katherine Salant
Saturday, January 27, 2007

"Use common sense to make sense."

It sounds like Ben Franklin, but the speaker is David Johnston, a green-building consultant in Boulder, Colo. His aphorism, he said in a recent interview, has proven to be a useful shorthand way of explaining sustainable green-building principles and practices.

Although these have been embraced by more and more home builders, there is still much confusion among the public as to what makes a house green. One way to keep things straight, Johnston said, is simply to remember to "use common sense to make sense."

For example, Johnston is asked regularly whether a green house is one that is free of petroleum products. His common-sense answer: "If you eliminate everything that contains petroleum, you can't enjoy the accoutrements of a 21st-century lifestyle." All the heating and cooling equipment and standard appliances contain plastic, he pointed out. "Even something as basic as a toilet has plastic parts."

Green building, Johnston said, has to make sense environmentally and economically. For example, building materials that have recycled content are generally considered to be a plus because recycling can significantly reduce both the volume of the waste stream and pressure on overflowing landfills.

But speaking like the hard-headed home builder that he once was, Johnston said you shouldn't select a product solely on this basis. A product with recycled content may be much more costly than the conventional product it is intended to replace, and it may not perform any better.

Materials have to make sense from a health perspective as well, Johnston said. Many building materials are made with unstable, volatile organic compounds, or VOCs. They can release gas into the air for weeks and sometimes years after they are installed in your house. Of the hundreds of VOCs that have been identified, the one that concerns most people is formaldehyde, a potent eye and nose irritant that can cause respiratory problems. It has been classified by the World Health Organization as a confirmed human carcinogen. You can easily avoid it by using one of the many building products now available with low or no VOC content, Johnston said. Though the non-VOC products often cost more, this is one instance where a higher cost is worth it, he added.

Moving from materials to other aspects of green building, Johnston talked about household energy use. His common-sense rule: Use as little as possible. His common-sense reason: It helps save money and the planet. If you use less energy, you will save on your utility bills. You will save even more as the price of natural gas, fuel oil and electricity inevitably go up.

If you use less energy you will help save the planet because you will be reducing the greenhouse gas emissions associated with your house. Johnston thinks that energy issues are so important, he urges homeowners to put them front and center in the design of any new house -- "from the first sketch of a floor plan to the final dotting your I's and crossing your T's."

But, Johnston added, energy savings should not come at the cost of having a great-looking house with lots of windows and views. The trick is to get all this and save energy.

Johnston's common-sense strategy for supplying household energy needs: Use what's free before using what you have to pay for. That is, tap as much free solar energy as you can for your heating and lighting needs before turning to conventional solutions.

To do this, you really do have to think about energy from the start because the feasibility of passive solar solutions depends on how you place your house on your building site, the first step in any building project. To capture the sun's rays for heating your house during the winter, your living areas must be oriented to the south. You can keep the same spaces cool in the summer by adding overhangs. With some additional refinements to the overhangs, the sun can also supply your lighting needs during the day.

To maximize the benefit of passive solar heating and cooling, you need to carefully tailor your building envelope to reduce heat loss or heat gain through the walls and roof. This generally requires adding insulation to the walls, attic and basement in amounts far above code requirements and upgrading windows to get ones with a low-emission coating that helps to keep the heat inside during winter and outside in summer.

Unless you live in Hawaii or Southern California, where passive solar strategies can supply all your heating and cooling needs, you will still need a furnace for those cold days when the sun's heat is not enough to keep you comfortable. But with your upgraded building envelope, you can use a smaller furnace and air-conditioning condenser, and that is a cost savings, Johnston said.

You will also need electric lights for nighttime use and cloudy days. Lighting accounts for about 12 percent of energy use in the average household. Taking advantage of the sun's light during the day shaves part of this, but you can shave it further with compact fluorescent bulbs, Johnston said. They use about 75 percent less energy to produce the same amount of light as an incandescent bulb and they last six to eight times as long. Compact fluorescents can be screwed into almost any conventional light socket and their color correction has vastly improved in recent years.

The other part of the home energy puzzle that green building can affect is the sizeable energy draw for hot water. The luxury of having 40 to 50 gallons available at all times consumes another 12 percent of household energy use. But, Johnston said, it's another instance where you can tap free solar energy by installing a solar collector on your roof. For cloudy days, though, you will need a back-up hot-water heater.

Another 35 percent of the energy that the average household consumes is out of a builder's hands, because it is the "plug loads" that homeowners bring into the house when they move in -- appliances, computers, home-entertainment equipment. The most effective way to reduce this load is to buy Energy Star products, available in more than 40 categories.

How does Johnston's "common sense to make sense" work in real time on a real house?

I contacted McStain Neighborhoods, a small production-home-building firm in Boulder that has constructed sustainable, green houses for more than 40 years. The firm builds about 350 houses a year in the Denver and Boulder markets.

Like all home builders, McStain takes a cost-benefit perspective. But, unlike almost all the others in the United States, McStain has a research and development department that carries out in-depth reviews of about 50 new products and building techniques a year. Periodically, the firm builds a test house that incorporates the most promising of these innovations. The test houses are eventually sold, but the firm continues to monitor them for several years afterward, said Barr Hall, McStain's head of marketing.

Jeff Medanich, who leads McStain's research efforts, said that much of his work is a balancing act, spending more here but saving more there so that, in sum, the cost of an innovation is relatively small.

Medanich offered as an example McStain's current exterior wall construction. Instead of the dimensional wood studs that are used by most home builders -- a single piece of wood sawn from a tree log -- McStain uses finger-jointed studs, which are made up of several smaller pieces of recycled scrap lumber that are glued together. These cost more, but their superior quality means that fewer are tossed as unusable -- about 4 percent, compared with 20 percent of the dimensional studs. The cost is a wash, but the finger-jointed studs have the added benefit of lowering costs down the line. Because they are straighter, the walls are plumb, and this makes subsequent work go more smoothly.

Katherine Salant can be contacted via her Web site,

2007 Katherine Salant Distributed by Inman News Features

© 2007 The Washington Post Company