We had the pleasure of working with Daniel Ernst, of Promethean Homes, on the energy modeling, specifications and testing for this house in Steeles Tavern, VA in the Shenandoah Valley. The “Passive Bauernhaus” (or “Passive Farmhouse”) houses seven members (across three generations) of the Ernst family. This house is the most energy efficient house I’ve worked on yet, and has the lowest HERS rating (34) of any house I know of in Virginia (without a PV system). It includes a smart balance of Passive House building envelope strategies to reduce heating/cooling demand combined with high-performance, but cost-effective mechanical systems and low-energy lighting/appliances. A PV system on a future barn will bring the house down to net-zero, or perhaps even into “plus-energy” territory.
Look for the full write-up over on Green Building Advisor.
Year built: 2012
Floor area: 2,676ft2
HERS Index: 34
Predicted annual energy use (HERS model): 9,554 kWh
Predicted annual energy use (PHPP): 8,320 kWh
Actual annual energy use: TBD
Blower door test result: 0.39 ACH50