2,100 Sq Ft Compact Passive Home

A compact passive house on the shoreline

This 2,100 Sq. Ft., 2 ½ story Passivehouse on long Island sound is shaped in part by zoning constraints, such as a total footprint of less than 1,580 Sq. Ft including garage, balcony and covered terrace.

The building walls and roof are made of prefabricated SIPS panels, with a 2×4 wall applied on the inside of the SIPS for piping and wiring. This reasonably priced assembly has an R 50 overall insulation with a thickness of just 10″. The SIPS shell was erected in just 4 days, saving 5 weeks of building framing.

With high performance windows and airtight construction, a single two ton mini-split heat pump was a good fit for the low heating and cooling needs. A gas fireplace provides back up heat, and solar thermal panels provide the domestic hot water. A 4 KW Photovoltaic system on the roof made it a net zero home


Project Specs

2,120 SF 1+1  bedroom Passivehouse

Peak Heating Load

20,700 BTU instead of 110,00 BTU

Annual (projected) Heating:

equal to 97 gallons of oil (4,014 KW) instead of 670 gallons of oil (27,500KW) – 87% less

Back up heating

45,000 BTU gas fireplace


Walls R=50 (10”) Roof R=50 (10”) Floor R=51 (13.5”)


Triple-glazed R=7.14 (standard window R=2.5)


One 2-ton Mini-split Heat Pump

Water Heater

Rooftop thermal  solar hot water collectors (2) with electric back up tank

Air Tight

<0.6 air changes/hour instead of 8 air changes/hour

Energy Recovery Ventilation

Automatic (86% efficient)

Photovoltaic (Solar) electricity

4 KW grid-tied system

Passivehouse features added +/- 10% to the construction cost  Solar system excluded)

Energy use comparison is based on a code complying house.