Yesterday we had a little bit of progress on site, our contractor came in and wrapped our foundation with bituthene waterproof membrane and did some preparation work for the plumber who will come out on Monday and requested that gravel be put in ahead of his work. So we now have a crushed rock bed for our slab when that comes in.
Yesterday morning we had another LEED meeting. This was our first productive one, and really it was a redo of a meeting that we had about four months ago to determine a rough idea of what our point count will be at the end of the process. We’re shooting for platinum, but we’ll see. There are quite a few advantages that our house has from the outset. First is its size, we have roughly 650sf of conditioned space which gives us an adjustment of -8 to our requirements for Gold or Platinum ratings. Plus then our location gets us an assortment of points. We did find out from this meeting that there was one potential large drawback to our plans… We’re building out of exceptionally efficient components (R-30 walls, U-0.17 windows) looking into the possibility of meeting the passive house standard, my heat loss calculations show that even the smallest mini split heat pump systems would be oversized for our needs at peak loading, so our response was to plan to put in small in-wall Cadet heaters. For LEED’s energy portion, they run a specific model that gives points related to the efficiency of your heating system and resistance heaters (in-wall Cadet) are roughly 100%, whereas their baseline is a 250% efficient heat pump. This might just make us upgrade to a larger, more expensive system for the sake of points.
LEED has done a fair amount of good to the building industry over the relatively few years that it has been in place. In the last decade green building has gone from a fringe group to the standard for new commercial buildings. Its also a fairly holistic rating system focusing on a variety of important aspects of green building from energy to water use to sourcing local materials. I have mixed feelings about the basis for the point system though. On one hand it gives people who may not really have a real depth of understanding of green building something to guide them through the process. On the other, it creates a bit of a culture around buying points… People with the money to do so are able to spring for that large solar array to offset other irresponsibilities. This all causes me to be a little uneasy about the deal with our heat system because we may be compelled to get the over-sized unit to score more points. In the end, however, we support the program because it has had a pretty positive overall influence on the state of building in the US.