Secondary suites within high-rise condominiums the size of a five-ton truck are coming to Vancouver.

In a move to increase the city’s rental stock and home affordability, city council approved Tuesday night the development of secondary suites within suites.

Vancouver architect Michael Geller, who pioneered the idea in the UniverCity development at Simon Fraser University, said people should think of them as “basement suites” or “mortgage helpers” in the sky.

Just as basement suites allow people to purchase a larger house, Geller explained, secondary condo suites could enable homebuyers to purchase a three-bedroom over a two-bedroom condo.

It would also increase rental stock in Vancouver.

The suites have their own bathroom and kitchen area and can be as small as 280 square feet. Geller compared them to a hotel room with kitchenette.

That minimum size could be further “relaxed” by the director of planning down to 205 square feet if the developer meets numerous livability guidelines, like adequate lighting and storage space.

Vision Coun. Raymond Louie said the suites would allow families to “age in place,” if they choose to do so.

Families could rent out the suite before they have children, expand into the suite when the family grows and rent it out again when their children leave the nest.

Louie said he expects it will be a year before the first development with secondary suites is built.

The city has previously approved secondary suites in the planned East Fraserlands development in South Vancouver.