Pembroke House is an 'Ultra-Low Energy', single-story house with a ground level area of 1,825 square feet and 625 square feet below ground.
Orientation: Long east-west configuration provides south-facing solar orientation to optimize passive solar heat gain through glass wall on the south elevation.
Envelope: 3-dimensional high performance thermal shell; typical opaque wall will achieve thermal resistance of R-45, roof assembly R-72, and ground slab R-40; air tightness change rate between 0.48 and 1.00.
Shape: Butterfly roof has south wing slope of 26 degrees for optimal winter solar gain deep into the house with solar gain storage in high mass floor; wide south roof overhang to protect the interior during hot summer months; north wing pitched at 50 degrees for optimal year around solar angle for either photovoltaic array for electrical generation or solar collection for heating water.
Systems: Air-to-water or ground-source heat pump for hot water in-floor radiant heating and integrated cooling; heat recovery ventilator for fresh air and humidity control; connection to electrical grid for redundancy.
Conservation: ½ of roof rainwater captured in storage tanks for vegetable garden irrigation and ½ distributed to rain garden.
The construction photos taken at mid-day on July 21, 2014 show roof overhang providing full solar shading of the south elevation.