Single Stair Accessible Flats
A Better Model for Missing Middle Housing
Single-stair accessible flats are a new model for gentle urban density, delivering spacious, family-oriented homes on small urban sites. By replacing double-loaded corridors with a single, efficient circulation core, these buildings create brighter homes with windows on multiple sides, improved cross-ventilation, and more flexible floor plans while making elevators and fully accessible suites more viable.
We see single-stair housing as an opportunity to design healthier, more sustainable communities that prioritize livability, accessibility, and high-quality infill housing.
In Vancouver recent building code changes allow for a single exterior stair serving a max of 4 to 6 units per floor.
A compact single stair and elevator core allows for homes to have windows on multiple sides of the unit.
Example ground floor plan showing the first level of the rear five-storey building dedicated to secure bicycle storage for all residents. The space accommodates e-bikes and cargo bikes and provides direct access from both the rear lane and the main foyer for convenient, everyday use.
The Prototypes:
50’ Lot: The “4/5”
Example floor plan with the stair, open hallway and elevator in the middle. Each half of the floor can hold one or two units. In this version there are three 1BR units per floor, all with windows or doors on 3 sides.
50’ Corner Lot: “The Corner Store”
Orphan Lots
50’ Lot: The “4/5”
Designed for Vancouver's typical 50' × 122' residential lots, the"4/5" prototype demonstrates how gentle density can be introduced within established single-family neighbourhoods.
The building steps from four storeys at the street to five storeys at the rear, reducing its visual impact while maximizing daylight, privacy, and livability. The five storey mass has larger sideyards that are 20 the width of the lot, which equals 10’ for 50’.
Site coverage is limited to 50% which:
Preserves green space
Supports Passive House/Climate-friendly design principles
Creates room for shared outdoor amenities, trees, and sustainable stormwater management.
Bike-first transportation, accessible design, and low-carbon construction combine to create a resilient housing model for the next generation of neighbourhoods.
Bike-centric housing, with parking for cargo bikes and e-bikes in common areas and within each suite.
The front roof of the four storey building can be a large roof deck (either common or private) and the upper roof of the five storey building can hold solar panels and heat pumps.
The "4/5" places two residential buildings side by side, with a green roof carport providing accessible parking from the lane and contributing to a greener, lower-impact site design.
50’ Corner Lot: The Corner Store
Where Neighbours Meet
The Corner Store reimagines the traditional neighbourhood corner by combining ground-floor commercial space with accessible single-stair homes above. Designed for walkable communities, it brings local shops, cafés, and services within easy reach while providing family-friendly, low-carbon housing on typical urban corner lots.
Orphan Lots
Small Lots. Big Opportunity.
Orphan lots remain underutilized despite being well served by transit, parks, schools, and existing infrastructure.
This prototype unlocks the potential of these overlooked sites, creating accessible, family-friendly housing with efficient layouts, generous daylight, and low-carbon construction.
For developers, it opens new opportunities on sites previously considered unbuildable.
For communities, it delivers gentle density that strengthens neighbourhoods without changing their character.
