Let small apartments share an internal wall.

A narrow Toronto zoning fix for sixplexes and small apartment buildings up to four storeys.

Read the ask See diagrams

The problem

Internal gaps waste narrow lots.

When two adjacent lots are developed together, required side yards at the internal lot line can consume width, complicate layouts, and reduce unit and bedroom count.

This is not about removing side yard protections for unrelated neighbours. It is about treating the shared internal lot line differently when both sides are controlled and designed together.

Existing precedent

Fourplexes already do this.

Toronto already permits semi-detached houseplexes: two multi-unit houseform buildings paired on a shared wall.

The same internal-lot-line logic should apply to sixplexes and small apartment buildings of comparable scale, provided both lots are developed together.

The proposed permission

The policy ask

Permit a zero side yard setback / party wall condition between two adjacent lots where:

  • both lots are under common ownership or part of one coordinated application;
  • each building is a sixplex or small apartment building up to four storeys;
  • the buildings stay within existing height, depth, and massing limits;
  • 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.

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.

Plan-view diagrams

Same form. Better lot-line treatment.

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.

Sixplex issue

Sixplexes separated by internal side setbacks Two adjacent sixplexes with side setbacks of 0.45 to 0.9 metres on each side of the internal lot line. 0.45-0.9 m side setbacks lost usable width Narrow internal gap between coordinated buildings

Sixplex setbacks can create a narrow internal gap with limited planning value.

Apartment issue

Small apartment buildings separated by wider internal side setbacks Two adjacent small apartment buildings with side setbacks of 1.8 to 2.4 metres on each side of the internal lot line. 1.8-2.4 m side setbacks larger lost width Wider internal gap on narrow lots

Small apartment side setbacks can consume materially more internal width.

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 more usable area fewer exterior walls Neighbour-facing setbacks preserved

The proposal changes the shared internal lot line, not the neighbour-facing setbacks.

Why it matters

Low-risk upside

Internal only

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

No added height

Uses the same basic built form more efficiently.

Lower cost

Two fewer exterior side walls can reduce cladding and construction cost.

Better units

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

Staff-facing FAQ

FAQs

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 already accepts comparable multi-unit houseform buildings in a semi-detached condition. This extends that logic one modest step.

Does it allow larger buildings?

No. Height, depth, massing, lot coverage, soft landscaping, and neighbour-facing side yards remain governed by the usual rules.

Why include apartment buildings?

In Toronto zoning, an apartment building has seven or more units. A seven- or eight-unit building can be similar in scale to a sixplex when capped at four storeys.

Does Building Code still apply?

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

Bottom line

Same form. Better internal lot line.

Party Wall Permission is a small technical fix: where two adjacent lots are developed together, the internal lot line should be allowed to work like a party wall.

That can mean lower cost, better layouts, and more homes without changing height, depth, or neighbour-facing setbacks.

Read the ask