There’s a futuristic house in Riverdale that looks like something from the moon. What’s it doing on Sparkhall Avenue?—Lisa Digiovanni, Leslieville

Meet the Healthy House, a showcase for technologies designed to ensure that our domestic putterings are carried out with optimal environmental sensitivity. The abode—actually a duplex—won a 1991 sustainable-housing competition sponsored by the Canada Mortgage and Housing Corporation. Designed by Toronto architect Martin Liefhebber, the off-grid dwelling (with on-grid backup systems) has rooftop solar panels to generate electricity and airtight walls to ensure energy efficiency (the heating bill for each 1,700-square-foot unit is a mere $80 per year). A backyard cistern collects rainwater, which is then purified and used for drinking and washing, and finally recycled for toilet-flushing duties. One of the units is occupied by the contractor who built the place, the other by a local couple. It’s still one of the few (almost) off-grid houses in the city; though with rising energy costs and dwindling red tape, that could change very soon—nothing like the bottom line to get you in touch with your inner tree hugger.

• Categories: Architecture