A proposal for Toronto

A small change.
More room
for homes.

Let multiplexes and small apartment buildings on Neighbourhoods-designated land share a wall. Put narrow lots to better use within the height permissions that apply to each site.

Read the proposal ↗ See the difference ↓
01 / The shared-wall ideaToronto, ON
Two small buildings joined by a party wallOne illustrative building form on adjacent lots, joined at the highlighted internal wall, with outer side yards retained. Building height follows the permissions applicable to the site; the illustration is not a height cap.A wall worth sharing.Applicable height permission
Shared internal wallIllustrative form · Height varies by site

01 / The opportunity

Make room.
Between the lines.

Two lots planned together shouldn’t need a gap between buildings that could share a wall. On narrow lots, internal side yards can take space away from rooms, circulation and practical layouts.

A shared wall could reclaim some of that width within applicable height and depth limits. The proposal retains required side yards facing surrounding properties.

Existing precedent

Fourplexes already do this.

Toronto’s zoning recognizes semi-detached houseplexes: portions of a building on abutting lots, separated by party walls, with up to four units per portion. See the City’s definition ↗

This proposal extends that shared-wall approach to multiplexes and small apartment buildings on land designated Neighbourhoods in Toronto’s Official Plan. It requires review of building-type definitions as well as setbacks, while retaining the height permissions applicable to each site.

02 / The policy request

One focused permission.
Clear conditions.

Permit a 0.0 m side yard setback and shared party wall at the internal lot line between two adjacent lots developed through one coordinated design, for multiplexes and small apartment buildings on Neighbourhoods-designated land, within the height permissions applicable to the site and subject to all other applicable requirements.

  • both lots are under common ownership or part of one coordinated application;
  • each building is a multiplex or small apartment building on Neighbourhoods-designated land, where the use is otherwise permitted;
  • the buildings follow the height permissions and other built-form requirements applicable to the site, including station-area policies where relevant;
  • the zero setback applies only to the shared internal lot line;
  • neighbour-facing side yard setbacks continue to apply;
  • Building Code, fire separation, access, servicing, and drainage review still apply;
  • building-type definitions expressly allow the shared-wall arrangement, with long-term maintenance and ownership issues resolved.

What changes

Changes

  • 0.0 m side setback may apply at the internal lot line.
  • Two coordinated buildings can share a party wall.
  • More of the permitted form can become usable floor area.
  • Two interior-facing exterior side walls can be eliminated.

Does not change

  • Maximum height or depth.
  • Rear yard or front yard requirements.
  • Lot coverage or soft landscaping rules.
  • Side yards facing unrelated neighbouring properties.
  • Building Code, fire, servicing, drainage, and access review.

03 / The difference

Keep the yards.
Lose the internal gap.

Existing precedent

Semi-detached fourplex-scale houseplex buildings Two adjacent lots with fourplex-scale buildings sharing the internal lot line. internal lot line party wall Already permitted for fourplex-scale buildings

Toronto already allows the basic semi-detached houseplex condition.

Multiplex issue

Multiplexes separated by internal side setbacks Two adjacent multiplexes with side setbacks varying with the applicable zoning. Internal side yards internal gap Narrow internal gap between coordinated buildings

Separate side yards can create an internal gap. Required setbacks depend on the zone, building type and site.

Apartment issue

Small apartment buildings separated by wider internal side setbacks Two adjacent small apartment buildings with side setbacks varying with the applicable zoning. Internal side yards internal gap Wider internal gap on narrow lots

Different building classifications can trigger different setback standards. Diagrams illustrate the principle, not a specific property.

Proposed condition

Same form limits with shared internal party wall Two similar buildings share the internal party wall and keep side yards at the outer edges. same height and depth party wall usable width shared wall Neighbour-facing setbacks preserved

A coordinated pair shares an internal wall. Outer side yards remain; usable area still depends on coverage, landscaping and other requirements.

04 / Why it matters

A little width goes a long way.

Internal only

Applies between two lots developed together, not against unrelated neighbours.

Use permitted heights

Works within the height permissions applicable to each site, including station-area policies where relevant.

Lower cost

A shared wall can reduce exterior envelope area. Actual savings depend on design and fire-separation requirements.

Better units

Less wasted width can support larger, more family-friendly layouts.

05 / Questions, answered

The details make
the difference.

Is this permission already in place?

This page advocates a policy change. It is not an adopted City permission. Existing permissions, geographic applicability and approval status must be checked for each property.

What if the lots are sold separately?

Staff review would need to resolve construction, ownership, maintenance, drainage and access arrangements. Common ownership at the application stage alone does not settle those issues.

Is this removing side yard setbacks everywhere?

No. It applies only at the shared internal lot line between two adjacent lots being developed together.

Why does the fourplex precedent matter?

Toronto recognizes semi-detached houseplexes of up to four units per portion. The sixplex provisions describe detached houseplexes. Staff would need to review both building types and setback rules to extend the shared-wall option.

Does it allow larger buildings?

The proposal seeks a shared-wall option within the height permissions that apply to each site. It could allow more usable width at the internal boundary, subject to lot coverage, landscaping and other applicable standards. It does not impose a separate four-storey ceiling.

Which land and building types does this cover?

The focus is multiplexes and small apartment buildings on land designated Neighbourhoods in Toronto’s Official Plan, where the use is otherwise permitted. Neighbourhoods is a specific land-use designation. The proposal is not limited to sixplexes or to a fixed number of storeys.

Can this include six-storey buildings near transit?

Yes. The proposal has no separate four-storey cap. Within delineated Major Transit Station Areas and Protected Major Transit Station Areas, Official Plan policy allows multiplexes and apartment buildings on Neighbourhoods-designated land up to six storeys within 200 metres of an existing or planned transit station, and up to six storeys on sites fronting a major street shown on Map 3. Site zoning and approvals still need to be checked. City policy summary ↗ · Zoning implementation ↗

Does Building Code still apply?

Yes. Fire separation, exiting, servicing, drainage, access, and emergency access still require technical review.

A better fit for Toronto’s lots

Let small buildings
share a wall.

A focused proposal for multiplexes and small apartment buildings on Neighbourhoods-designated land. More room for practical layouts, within the height permissions and built-form requirements applicable to each site.

The next step: ask Planning staff to review a shared-wall permission and the related building-type definitions.

Return to the proposal ↗