Net-Zero Rebuild

This project began with the decision to rebuild, rather than demolish, a 1970 bi-level structure. The house sits atop the north bank of Mill Creek and has unimpeded south exposure and views of the forest below.

Changes made to update the structure:

  • Removal of stairs to front door and basement, and partitions in main floor
  • Heat-absorbing triple pane, low-E fibreglass windows installed across south and west walls, for passive solar heating. Replacement of all other windows
  • New basement concrete slab with insulation beneath and radiant heat system
  • Dyed, polished, and heated concrete main floors
  • All new water and sewer lines and electrical wiring throughout
  • 5 inches of polystyrene insulation with rain screen applied to all exterior walls
  • Raised roof to support solar photo-voltaics and provide summer shade
  • Steel roofing installed and acrylic wall finish 

To achieve ‘net zero’ energy use:

  •  Air-tight building practices and window installation
  • Heat recovery ventilator with ducting to all rooms
  • 6-zone in-floor heating and domestic hot water by wood pellet boiler – waste wood with current renewal and carbon uptake - rather than fossil fuel
  • Concrete floors acting as solar heat sink at both levels
  • Low-flow toilets and faucets, and high efficiency washers. No clothes dryer
  • High efficiency, low particulate free-standing wood stove on main floor
  • Thermal chimney: remote controlled opening window at top of high ceiling to naturally expel hot interior air during warm weather
  • 5 kilowatt PV panel system facing south at 30º, tied into electrical grid
  • LED and mini-fluorescent lighting and motion detector interior switching

The house is now comfortable in any weather and filled with natural light. The solar generating system, in the six months since it was commissioned in February, has produced about twice the power used and bills for the past three months are credits.


Completed February 2014