Net Zero PV Log Home
Is there anything more luxurious than spending time in a well-built home?
Standing proudly on a hill surrounded by gorgeous mountain views, situated in one of the coldest areas of Colorado, the Fraser-Granby mountain valley, is a surprisingly efficient house.
The contemporary active-passive solar house is situated and built to be cool in the summer and warm in the winter. It is a grid-tied (connected to the local electricity utility) house that is both efficient and comfortable.
The home achieves net-zero energy use in the summer by using two different forms of active solar electricity: solar photovoltaics to create electricity, as well as evacuated solar tubes, to heat the house with radiant heat and supply hot water for domestic use. (To be technically accurate, it is actually net-less-than-one, rather than net-zero. Although it could achieve net-zero and it’s really darn efficient!)
This two- part article will explore different aspects of active PV, solar evacuated tubes and the passive solar features of the grid-tied home. Oh yes, we’ll get into the guts and inner-working parts of the house in part 2.
Passive Solar Aspects of the House
I visited the house both during the summer and in the winter to learn about its solar gain.
The southern side of the house contains most of the windows, while the north side of the house (picture below) has a minimal amount of windows.
If southern facing windows have a properly planned overhang, it can be situated in a way that blocks the summer sun, yet allows the winter sun to reach deep into the house.
The porch on the southern side of the house is covered by an overhang that blocks the summer sun’s rays from entering the house, yet in the winter when the sun rotates a lower arc across the sky the sun’s heat can enter and heat the house.
This house has been built in a location has often been referred to as the “Ice Box” of the nation.
Because windows are a liability in colder climates, they are typically the biggest source of heat loss in a building (besides an open door).
The lack of windows on the north side of the house help minimize heat loss out the coldest part of the house.
Most of the windows in this home are fixed (with no openings) and triple paned.
This picture was taken five days after the winter solstice and shows the winter sun’s rays penetrating deep into the house.
In addition to passive solar winter heat from the sun, there is radiant in floor heat within the two floors that comprise the main living areas.
The kitchen flooring is travertine, a rock-based material that has density and thus, thermal mass to absorb the sun’s heat, also helping to keep the house warm in the winter.
This combination of design and its materials complement the home’s overall efficiency.
The home gleams of luxury, with its marble counter tops, its slate stone tiled custom shower in the guest room, yet this house also includes scavenged materials.
The owner builder used scavenged, high quality materials that were headed for the scrap-yard unless they were used. The guest shower has been made from ‘dumpster’ slate. The owner-builder said that the tiling the shower took a lot of planning, with a week of time spent arranging and grouting. Yet the shower, which I used, was luxurious. Had the owner not told me that it was dumpster slate, I would have thought every piece was cut exactly for the place and purpose it is in.
It’s also worthy to note that almost all the lights in the house are compact fluorescent, using approximately 70% less energy than conventional light bulbs. The newer, more efficient kitchen appliances also use less electricity.
Using Locally Sourced Materials
The house is built almost entirely from beetle kill pine, and its blue tinged wood line the inner sanctum.
The wood for the railings, posts, stairs & cabinets come from nearby because the house is located in one of the areas in Colorado that has been drastically impacted from the ‘beetle-killed’ pine trees. While having drastic ecological impacts, this situation has also created a surplus of timber. The most of the lumber for this house was milled locally, and the trees did not travel far, likely coming from within a 75 mile radius where the house was built.
To learn more about the mechanics of the house, continue to the next post in this series:
Owner built house with two principle builders
House Square Feet – 3,700
Time on Build – Two years while working different full time jobs