Notes from Windward: #58
Working on the dining hall
This will give you a rough idea of the general layout of the cement work that's going into the dining hall. One of the challenges that comes with sustainability is that there's a lot of work and investment that goes into creating a sustainable structure. By taking the time and expense to build an earth-sheltered building, we'll be able to avoid the hefty power bills that come with standard construction. There's a lot to be said for renewable ways to generate energy, but it's aways better to build in such a way that you don't need the energy in the first place.
The entire north side of the dining hall has been constructed out of a six foot high, steel reenforced, concrete retaining wall. When completed, this wall will be coated with tar and plastic. This will work in conjuction with a water diversion pipe installed on the outside along the footing of the retaining wall to insure that ground water doesn't get into the building and create a dampness.
Once the wall is sealed, lots of earth will be brought in and backfilled against it. When that task is complete, about five feet of earth will insulate the dining hall all along it's cold, northern side.
All sides of a building radiate heat, but at least on the southern exposure, the heat loss is offset by heat gained during the day. Since the north side of a building doesn't receive any direct sunlight, it doesn't collect any heat during the day. Instead it acts as a heat sink both day and night. By earth sheltering this northern side of the building, the heat that moves through that side of the building is retained in the earth.
The average year-round temperature of the soil here is about 55 degrees. During the winter, the north side of the dining hall will remain warmer because it is in contact with the relatively warm earth instead of the frigid winter air. In summer, the same thing happens, only in reverse as the comparatively cool ground absorbs the summer afternoon heat.
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