After working on this house design and construction project for over two years, it looks as though a dozer and shovel will hit the ground over the next two days. We are very excited.
We met with our builder Jonathan Good, of Good Construction & Manufacturing, this weekend and managed to “shoe-horn” the project into our strict budget. The result is a fine balance between the builder doing most of the work, and the owner chipping in on a select few projects to save on labor costs. We will also be assuming some of the purchasing responsibilities to reduce the general contracting burden. This, and having reduced the overall size of the house by 10%, finally got us under budget. I’ll be challenged with the responsibility for plumbing, hardwood flooring, tiling, partial insulating, and installing the radiant floor system – but we managed to cut enough costs that I am no longer responsible for the metal roof installation in the middle of January.
Perhaps the biggest single reduction in cost was an altered approach to insulation. We had originally spec’d a 15.5″ wall cavity filled with dense-packed cellulose for an R52 wall. However, because we were over budget and looking for ways to reduced costs, I began to rethink this somewhat. Earlier this fall, I had purchased a truck-load of used 5.25″ Type II EPS foam boards (R20) to use for for insulating under the concrete pad. (These were used boards that came off a local hospital roof) To get this ‘deal’ I had to purchase 3 times as much as I needed, but the price was right and I was happy to use the surplus on other projects such as a future shop and music studio. But given our budget challenge we determined the best way to use these materials was in the wall system. As such, we’ll reduce the depth of the wall by 3″ and install 5.25″ of foam within the wall cavity inorder to reduce the amount of cellulose that needs to be blown in. The end result is an R48 wall at 1/2 the insulation cost. We’ll still use dense-packed cellulose, but only 4″, in addition to the foam and 3.5″ of roxul. And we gain about 60 square feet of living space with the extra 3″, so the trade-off is ok. This foam has been a project saver.
If you’re looking to build super-insulated or to insulate under a concrete pad, it is worth while to check around on kijiji or other used sales websites for used foam board. Or check with local commercial roofing companies – I had heard this through the grapevine over the last few months and it turned out to be true. I bought used R20 foam board for a 1/4 of the commercial price, and brand-new 1″ XPS board (seconds) for 40% the commercial price. Between the walls and the concrete pad, this used foam purchase will save us over $15,000 and make for a very tight wall system, and super warm floor. And if you’re looking to get LEED certified (we’re not at this point), these used or recycled products will likely earn you extra points towards accreditation.
Construction photos to follow.