We tried as much as possible to use building materials that would have the least negative impact on the environment. Concidentally, these materials are also better for indoor air quality, which is great for those people with sensitivities. Richard Nuesch of Sound Home Construction was very helpful in providing different options for us, while still being sensitive to our budgetary limits.
We opted for a concrete slab for the foundation rather than a basement. For the square footage, a second storey is less expensive to build than a basement, and basements do tend to be damp - a perfect environment for molds.
We had tossed around lots of different ideas for the walls. Initially, we were quite interested in cordwood masonry (or stackwall) construction, but in the end we went with straightforward 2-by-6 stud construction. We chose cellulose insulation for the walls and the ceiling. Although a little more expensive than fiberglass batts, cellulose (made of recycled newspaper) is a loose-fill insulation that is blown into the wall cavities. It is less likely to result in cold spots, because it fills every single nook and cranny. It is also much safer to work with. Airborn fiberglass particles are nasty on the lungs, and are so small that it's almost impossible to completely get rid of them.
Interior walls are finished with a combination of pine boards and drywall. Exterior walls are sheathed in exterior-grade plywood and finished with cedar shingles.
The roof is covered with steel sheets. You may hear people refer to it as a "tin roof". Our roof is expected to last a good 50 years - low maintenance, and much more environmentally friendly than asphalt shingles.
Inside, we tried to avoid engineered wood products like engineered floor joists and melamine countertops which contain a large amount of glues and other toxic substances. Floor joists are solid wood, in a post-and-beam style (posts are solid tree trunks from our own woods). Our second floor is simply 2-by-6 pine decking, of which the underside is the first floor ceiling. Easy to install - one step finishes everything - and it looks great! The countertop was made by our friend Alexander Reuss out of solid birch. It complements our solid pine cupboards quite nicely.
All interior wood surfaces were finished with all-natural products from Eco-House Inc., P.O. Box 220, Stn. A, Fredericton, NB, E3B 4Y9. Their finishes contain ingredients such as linseed oil, citrus thinners, pine resin and essential oil of rosemary. They now have all-natural paints too!