William McCullam
This submittal consists of five (5) homes on the three lots. All five homes have similar floor plans.
McCullam/Jenkins-LEFT shows:
- A duplex (2 family) home with an attached rental unit. Alternatively this building could be sold as two (2) separate, but attached living units. In the latter case there would be a shared drive.
- The duplex contains a 1,650 SF, 4 bedroom/2 full bath unit with an attached 1,250 SF, 2 bedroom/ 1½ bath rental unit.
- The four-bedroom unit has a fully handicapped-accessible ground floor with a bedroom and full bath, and 3 bedrooms on the second floor.
- The house has a heated slab on grade with gas furnace and hot water, and a mini-split AC system.
- The duplex is designed to be very highly energy efficient. It features a double stud wall with high-density cellulose insulation.
PassivHaus (PH) standard at market rates is a fallacy based on very high initial embodied energy. The average new home uses around 80 tons of embodied carbon, or 70 pounds CO2e per square foot. “Market rate” PH model homes are almost 120 tons.
- Our goal is 35 tons embodied carbon. For an equivalent PH residence, this would give a total life cycle energy cost + embodied carbon in the range of 17-21 years.
- Goal is 2 air change per hour (ACH) infiltration vs. 0.6 ACH for PH
- PH sets design at 1.4 kWh/SF. Our goal is 3.0 kWh/SF. This results in total energy costs of between $700-1,000 annually vs. less than $500 for a PH.