The goal of the Thousand Home Challenge is to reduce the energy usage of 1,000 homes by 70 to 90%. It outlines two paths to meet the challenge. Option A is a specific reduction from current usage. We’re going to ignore that since we’re building a new house.
Option B seems to blend aspects of both passivhaus and net-zero. It is based on a low energy target and verified using actual energy usage data over a year. Renewables like our solar PV array, count as credits toward meeting our target. (I think the net-zero house movement would benefit from having a low energy target to avoid the ‘6,000 sf house with a 20 kW array’ problem.)
The target is based on a combination of climate, size, number of occupants, heat source and whether it is attached or detached. They have a handy spreadsheet you can download at the thousand home challenge website. Just punch in your numbers and it will tell you your target.
Here’s the run down on our inputs.
- Climate – The closest weather station data was determined to be North Adams, Massachusetts, but I chose Glen Falls, New York, since this is what we used in the original energy calculations.
- The home’s finished floor area is 1,200 sf.
- Two occupants, not counting critters.
- Detached single home.
Based on that scant information, the threshold calculator produced a target value of 5,619 kWh/year (site energy) if using electricity for heating. This works out to roughly 19.2 million BTUs/year.
If you remember back to our earlier energy posts, our energy consultants estimated our yearly energy use at 5,995 kWh/year, or 20.4 million BTUs/year.
So if we ignore the solar PV array, we would be roughly 376 kWh short of meeting the Thousand Home Challenge.
I like a challenge, so I’ve signed us up for more information and to start the application process. I’ll post more info as we progress through the process.