How the projections rules are organized

Ottawa's zoning bylaw has a general provisions section on permitted projections into required yards. That section lists the categories of building elements that are allowed to encroach, the maximum encroachment distance, and any conditions (for example a minimum distance to a lot line that must remain).

You should read this section as a companion to your zone table. The zone table gives you the minimum yard distance. The projections section tells you what can poke into that yard and how far.

• Zone table: the minimum yard is (for example) three metres.
• Projections section: an eave may project up to a certain distance into that yard.
• Combined effect: the building's wall respects the setback, but the eave can extend closer to the property line.

Eaves, gutters, and roof overhangs

Eaves are one of the most common projections. The bylaw typically permits eaves and gutters to encroach into required yards by a modest distance, provided a minimum clearance to the lot line is preserved. This matters most on tight urban lots, where a proposed addition can technically clear the setback at the wall while the eave violates the projection rule.

If you are designing a hip roof or a deep overhang, model the overhang, not just the wall, when checking setbacks.

Decks, patios, porches, and balconies

Deck and porch rules are more nuanced. A deck close to grade is often treated differently from a raised deck, and a covered porch may be treated as building area rather than a projection depending on its size and enclosure. Balconies at upper storeys usually have their own allowance because their impact on neighbours is different from a ground-level deck.

The pattern in most zones is: a modest encroachment is permitted for uncovered decks, larger encroachments require variance, and full enclosure often converts the structure to building area subject to the standard setback.

• Grade-level decks: often the most flexible.
• Raised uncovered decks: usually allowed to project modestly.
• Covered porches or roofed decks: check whether they count as building area.
• Balconies: separate rules, often with their own maximum encroachment.

Stairs and landings

Exterior stairs and small landings that serve a required entrance are usually allowed to encroach further than the deck they connect to. This is a life-safety accommodation: the bylaw recognizes that safe egress needs a stair, so it makes room for one within the required yard.

For accessory unit projects (basement apartments, secondary suites), the exterior stair to the entrance is often the tightest constraint on the side yard. If the numbers are close, it is worth checking early rather than at permit stage.

HVAC condensers, generators, and mechanical equipment

Air conditioners, heat pumps, and generators are treated as mechanical equipment. The bylaw allows them to project into required yards, but usually with a required clearance from the lot line and often with noise or screening conditions.

If you are placing a new heat pump on a tight side yard, confirm both the projection allowance and the noise setback. Some outdoor units have manufacturer specifications that force a larger effective clearance than the bylaw minimum.

Chimneys, bay windows, and architectural features

Chimneys, bay windows, cornices, sills, belt courses, and similar architectural features usually have modest permitted encroachments. The exact numbers are in the projections section of the bylaw. The important idea is that these are architectural, not structural in the sense of counting as building area, so they get their own smaller allowance.

When a variance is needed

If your projection exceeds the permitted allowance, you need a minor variance from the Committee of Adjustment. Whether the variance will be granted depends on the four tests: does it maintain the intent of the Official Plan, does it maintain the intent of the zoning bylaw, is it desirable for the appropriate development of the land, and is it minor.

Small overshoots on a projection can sometimes clear the four tests without much drama, especially with supportive neighbours. Large overshoots or projections that push a building form clearly outside the norm for the block are harder cases.

• Small numeric overshoot: often a candidate for a straightforward variance.
• Larger encroachment or blockable projections: harder case, plan for a longer process.
• Consider whether the design can be adjusted to fit within the allowance rather than pursue a variance.

Frequently asked questions