Every number that decides what fits behind your house.

How big can a laneway house be in Burnaby?

A laneway or coach house in Burnaby is regulated as a rear principal building and may reach 7.5 m with a sloping roof or 7.0 m with a flat roof, over two storeys including any basement. It must sit 1.5 m from the lane, 1.2 m from each side lot line, and 6.0 m clear of the house in front of it. Its footprint is limited by lot coverage, 30% on lots over 567 m² and 40% on smaller lots, counted across every building on the property. Burnaby Zoning Bylaw No. 14815 sets no maximum floor area and no floor space ratio for this district.

The full dimensional table

Quoted from Part 3, Section 1.1.5 of Bylaw 14815, R1 district. Unless a row says otherwise the figures are for a lot with one to two dwelling units, which is the ordinary case of an existing house plus one new laneway home.

Why 7.5 m is more generous than it sounds

Height in Burnaby is not measured to the ridge. Part 3-1.1.7.1 of the bylaw measures a sloping roof to its midpoint, defined as half the vertical distance from the top plate of the uppermost storey to the highest point of the roof. A pitched roof therefore carries its peak above the 7.5 m line, and the steeper the pitch the more room there is above the number.

That is also why the sloping allowance is half a metre taller than the flat one. A flat roof is measured to its highest point with nothing above it, so the two limits are closer in real terms than the figures suggest.

The measurement starts from the lower of the average front or average rear elevation, using the lower of natural or finished grade. On a sloping lot this matters more than the limit itself: the datum is taken from the low side, so a lot that falls toward the lane gives the rear building less usable height than the same building would get on flat ground. Check the grade before trusting a two-storey assumption.

The storey count is the harder constraint for most designs. Two storeys is the cap and it includes a basement or cellar, so a laneway home with a full basement has spent its allowance on the basement and the ground floor. The bylaw does allow the ground next to a building to be lowered for basement access without affecting the height calculation, provided a vehicle access is no wider than 6.7 m along the wall and a pedestrian access covers no more than 10.0 m² per primary dwelling unit including stairs.

The 6.0 m separation is what usually decides it

Of all the figures on this page, the separation between the front and rear buildings is the one that ends the most projects. Six metres of clear space is required between the two, measured from the nearest point of each building face, and the bylaw explicitly forbids putting an accessory building inside it.

Work it through on a typical lot. Take the depth of the lot, subtract the existing house, subtract 6.0 m, subtract the 1.5 m lane setback, and what remains is the maximum depth of the new building. On a shallow lot that remainder can be too small to hold a plan, no matter how much height or lot coverage is theoretically available.

A short list of features may project into the separation: steps and stairs, outdoor appliances, arbors and similar minor landscape features, window wells, and decks or terraces up to 1.0 m above grade. Higher decks and canopies may take up to 25% of the separation's width. Belt courses, cornices, sills, chimneys and bay windows may take the lesser of 0.9 m or 25%, and eaves the lesser of 1.2 m or 25%.

Where the existing house sits too far back to leave 6.0 m, the options narrow to reducing the rear building's depth, altering the existing house, or accepting that the lot does not carry a second home. The feasibility sub-guide sets out how to test this in an afternoon rather than after paying for drawings.

Coverage and permeable surface work against each other

Lot coverage caps how much of the lot the buildings occupy. Permeable surface sets a floor under how much of it stays able to absorb water. On a lot with one or two units those figures are 30% coverage for lots over 567 m² (40% for smaller lots) and 40% permeable, and the space between them is where the driveway, patio and walkways have to fit.

Note which way the coverage rule runs. Larger lots get the lower percentage, so a bigger lot does not produce a proportionally bigger pair of buildings. A 600 m² lot is allowed 180 m² of coverage at 30%, while a 560 m² lot is allowed 224 m² at 40%. The smaller lot may build more.

Permeable surface is the requirement owners underestimate most, because the paving that serves a second dwelling is easy to leave off a sketch. Add the parking pad, the path to the lane, the required 1.0 m fire access corridor and each unit's outdoor amenity space, and the hard surfacing can breach 60% of the lot before anyone has drawn a patio. Permeable paving is the usual remedy, and it is cheaper to plan than to retrofit.

Fire access and the 45 m sprinkler line

Part 3-1.1.5.6 adds two requirements that shape the site plan rather than the building. Every dwelling unit needs a fire access corridor at least 1.0 m wide, paved or gravel, running from the unit's entrance to a lot line abutting a street, or to a constructed lane where street access is not feasible. It has to stay clear of projections and obstructions to a height of 2.5 m.

Any dwelling unit more than 45 m from a lot line abutting a street must have an automatic sprinkler system. On a deep Burnaby lot a rear building can cross that line, so measure it early: a sprinkler system is a real cost and it also means a water service sized to feed it, which loops back into the servicing question covered in the parking and servicing sub-guide.

If your house is on the Heritage Register

Lots on the Community Heritage Register can be granted relief from several of these rules, subject to approval by the General Manager Planning and Development and a Section 219 Covenant protecting the heritage resource. Lot coverage may rise to 60% with permeable surface reduced to 30%, street yard setbacks may fall to 2.0 m, the separation between buildings may be reduced, off-street parking may be waived entirely, and the three-bedroom requirement does not apply.

Original architectural features such as chimneys, railings and decorative appurtenances may also be excluded from the height calculation. For an owner of a character house who wants to keep it and add a second dwelling behind, this is the most generous part of the bylaw, and it is worth checking the Register before assuming the standard numbers apply.

Frequently asked questions