UPDATE 2013: We’ve moved! The Stow house is still AWESOME, it just has a new owner enjoying it!
Where? Stow, MA
When? Completed June 2010
What? Almost Passivhaus, almost net-zero energy, 2.5 floors and a basement 30′x22′ interior dimensions. 6.9 KW PV installation
- Architect: Kraus Fitch, Amherst MA
- Builder: Transformations Inc, Townsend MA
- Passive House Energy Modeling: DEAP Group, Newton MA
- House Monitoring: Fraunhofer CSE, Cambridge MA
- IAQ monitoring; Plug-in-load monitoring: Lawrence Berkeley National Laboratory, Berkeley CA
HERS Index: 9 (though I have noticed the size of the PV array and some of the insulation levels are wrong in the report, so probably lower)
Energy-Star-Homes: Tier III (June 2, 2010)
PHPP: “Specific Primary Energy Demand” 36.8 kBTU/sqft/yr
Blower Door: 180 CFM50. 0.71 ACH50 (using PassivHaus volume) 0.50 ACH50 (HERS volume)
Climate — HDD: ~7300 base 68 for Worcester MA
Actual 1 year results (6/2010-5/2011): 10,000 KWh site energy used. 8,300 KWh site energy produced. 1,700 KWh net used. I believe our electricity bill for the entire year for EVERYTHING (including lawn mowing!) was $400. And that’s not even for net metering. Hudson Light and Power pays one back for electricity going to the grid, but not at the same price you pay for taking, so even on a month where we make more than we use, we usually have an electricity bill unless it is WAY off.