Dubbeldam Architecture + Design

Skygarden House

The renewal of this 100-year-old, 225m2 three-story residence on a small urban lot, is a transformation of an old leaky house into a highly efficient home, using a few active sustainable systems (radiant floor heating) integrated with multiple passive sustainable strategies to maximize cost and energy savings .


A central light and air shaft – an open-riser stair topped with large operable skylights coupled with strategically placed operable windows – creates a stack effect in the cooling season, drawing warm air upward and cool air in the lower levels. The light shaft also brings natural light deep into the center of the house to optimize daylighting. The large glazing areas provide passive solar gain in winter and solar exclusion in summer (with the help of a large tree). High-performance insulation, an airtight building envelope, and mechanical ventilation with energy recovery reduce mechanical air conditioning and increases comfort levels.


The house’s mechanical and electrical systems are completely integrated with passive design strategies to achieve the most efficient methods of heating, cooling, and lighting while minimizing energy costs. Natural ventilation through operable windows and the central air shaft significantly reduces energy use compared to a standard air conditioning system. The green roofs and high-performance insulation help to reduce heat loss and gain through the building envelope. Photovoltaic panels on the roof were planned for the future – rough-in wiring was installed to allow for future installations, as well as for a Tesla battery to store electricity during lower-cost time periods. The integration of these systems results in improved building performance, energy conservation, and occupant comfort with an annual energy consumption of only 75.8 MJ/m2 (taken from the owner’s utility bills).


Life Cycle Analysis was a strategic part of the renovation process. The existing masonry exterior sidewalls of the house were maintained and existing appliances, doors, furnace, and radiators were donated. FSC-certified lumber and flooring were used; the interior wood cabinetry products are formaldehyde-free. The plumbing runs through PEX tubing made from cross-linked HDPE polymer rather than copper (lighter weight for shipping and less material used in installation).

The exterior wood is thermally-treated ash, made from the destruction of ash trees due to the emerald ash borer disease. All plumbing fixtures are low flow to minimize potable water use. Domestic hot water is supplied ‘on demand’ from the radiant heating system boiler, reducing potable water waste due to wait times. In the design of the landscape, rainwater collection for irrigation is incorporated in a cistern at the back of the yard, reducing potable water consumption for plants.