The Green Column 1/27/2011

The Green Column

by Richard C. MacCrea, Andrews Valley Initiative

rmaccrea1@gmail.com

Builders Need to Learn How to Build Affordable and Green

What do you think of when you hear “green?” Solar panels. Geothermal heating and air conditioning. Increased cost. But most people cannot afford extra costs, and most of the rest are not willing to pay for them. In this economy we need to learn how to build green without spending extra. How?

Most importantly, pay attention to the sun. Plan the house so more sun hits it in the winter, and less in the summer. Each site is different but any home could be planned better without increasing costs. Try to make more of the glass face south as directly as possible. Design the roof overhang just big enough to keep the sun off the southern glass in the summer. Increase the overhang as much as possible on the west and east sides. (Porches would even be better). Try to protect the north side with evergreen foliage, earth, or anything else that can cut the cold winter wind. Following these principles will not add to the construction costs of most homes, but can reduce the cost of heating and cooling a lot. The more this can be applied, the better.

The second most important principle is to make the house more air tight. I like spray foam insulation. It easily plugs up all the drafty holes. It costs a little more, but a smaller heating and air conditioning system can help make up for the difference. Choose better  windows and doors by comparing the energy ratings. (Next week’s column will explain window energy labels). Crank out casement windows tend to be more airtight and provide better ventilation than double hung windows. Substituting some of the windows with double pane fixed glass can make up for the extra cost.

The third way to be be green on a budget is to improve the design of the heating ventilating, and cooling (HVAC) system. The system should be installed completely inside the insulated areas of the home (including the duct work). The HVAC contractor should size the system to the exact load of the house. A computer program calculates the load based on the insulation, windows, doors, roof overhang, and the directions each wall faces to calculate how big your HVAC unit must be to keep up. It is very important that your system be just the right size. An HVAC unit that is too large will cost more to install and run, and it will not be able to keep the house as comfortable. A properly sized and well balanced system will keep each are of the home more comfortable efficiently.

These three principles can make most homes a lot more efficient without increasing construction costs. But what if you still want to have a geothermal system, or solar panels but you cannot afford them? (Following the principles in this article will reduce energy consumption so much that a smaller geothermal system or fewer solar panels would do the job). To afford these extras look at cutting wasted square footage from your plan. Many homes can be easily reduced in size to save costs. (See last week’s column).

Richard C. MacCrea is the director of The Greening of  Andrews Valley, a program of Andrews Valley Initiative. He works in the field of energy efficient, green building. rmaccrea1@gmail.com