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 in PHPP: 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 quite a bit 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, like a sunny August where we are away for 2 weeks.