Wednesday, September 19, 2012

Affordable solar housing

Last Monday, I wrote about a really nice home that had won a bunch of awards for energy efficiency.  It was beautiful and stunningly well-built but it probably cost at least $750,000.  So I wrote my brother asking, "Don't you have any examples of affordable energy efficiency?"

So he dug through his examples and came up with this really clever house put up by the Habitat for Humanity folks.  This is probably one of the best homes they ever built.  Modest, solid, with a HERS rating of 18 (remember, most new housing comes in at around HERS 100.)  The excuse that energy-efficient housing is too expensive took a major hit with this place.

The latest certification we received was for a 1214 sq. ft. 3/2 Habitat for Humanity in Seminole County home in Sanford, Florida. This home is a replacement home for an abandoned house built in the 50’s. That house was demolished and this one took its place, so we were able to get points for Infill lot, close to infrastructure and community resources. From foundation to Certificate of Occupancy was just over 6 weeks and the vast amount of labor was donated through the efforts of local Radio 104.1 and their Morning team, Monsters in the Morning, thus the moniker ‘The Monster House’.

The basis of the home is ICF (Insulated Concrete Forms) walls, 8” thick walls made up of 2 layers of Styrofoam which are stacked like blocks (they remind me of Lego) and then steel placed at prescribed distances (both horizontal & vertical) and then filled with concrete. This process has several advantages, certified wind resistance to 130 mph, no thermal bridging, R-22, no strips on the wall for bug super highways, the drywall attaches directly to the Styrofoam, and if a person was a bit handy, could erect the walls by himself in a couple days, just follow the manufacturer’s directions.

This house’s walls were erected in one day by a crew of 6-7 and a small crane. Here is the link to the ICF walls supplier There about 20 or so manufactures in the US, so finding them should be pretty ease, here is another They all make claims of being the best, so do your homework. There are starting to actually be products that do what they say they can, and this one & AAC are 2 of them. This one is actually also one to be considered a do-it-yourself product.

Then the rest of the house was completed, using standard trusses, R-38 attic insulation, a radiant barrier system, SEER 14 HVAC system, Low e vinyl windows, 2’ overhangs, a donated Solar Hot Water system, and a donated 2.8 KW PV system and donated Energy Star appliances. Every light in & out of the building are LED. There is no irrigation system, low flow shower heads, lav faucets & 1.28 gpf toilets so water consumption is low too When everything was said & done, I gathered all the pertinent info, submitted it all the the Florida Green Building Coalition and we were awarded a Platinum Certification with 194 points, also a Water Star Certificate, Energy Star V3, and a HERS Score of 18. The HERS is 54 without the PV system. Pretty incredible for a Habitat Home.

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