Fire Sprinklers, Smoke Alarms and CO Alarms in a BC Custom Home

A client in Parkcrest asked us last spring whether their new house would have fire sprinklers. They expected a yes or a no. What they got was "show us the site plan," because in Burnaby the answer depends on where the house sits on the lot, and in the next municipality over it depends on which side of a line on a map the lot falls.

Life safety in a new house has three parts: sprinklers, smoke alarms, and carbon monoxide alarms. The alarm rules come from the BC Building Code and apply to every house we build. The sprinkler rule comes from the municipality and changes from city to city. All three get decided before rough-in.

Whether sprinklers are required depends on the city, and sometimes the lot

Burnaby's rule is narrow. Under the R1 Small-Scale Multi-Unit Housing District of the Burnaby Zoning Bylaw, a dwelling unit located more than 45 metres from a lot line abutting a street must contain an automatic sprinkler system. On a typical lot in Parkcrest or Capitol Hill, the house is nowhere near 45 metres from the street, so sprinklers are an option the owner can take or leave. A rear building on a deep lot, or a panhandle lot with a long driveway, is where that distance starts to matter.

The District of North Vancouver takes a different position. Its building bylaw requires all single-family homes in its fire limits areas to be sprinklered, and the same document spells out the details: the system is installed to NFPA 13D as referenced in the BC Building Code, each dwelling unit has its own sprinkler water supply, and a tank-type toilet has to be fed from the sprinkler head farthest from the main supply. Garages are left out, and a single-family house needs no fire alarm panel on top of the sprinklers.

For every other city we build in, we pull the municipal building bylaw and confirm the rule for that specific lot before the drawings are priced. Finding out at permit review is the expensive way to learn it.

Sprinklers also come up on houses where nobody requires them. The 2024 BC Building Code permits NFPA 13D for a residential building with no more than two dwelling units, and a house built to it counts as "sprinklered" under the code. The Building Code Appeal Board's decision 1863 confirmed two things worth knowing. First, where fire department response time is over 10 minutes, the code treats an exterior wall as if it sat half as far from the property line as it does, unless the building is sprinklered. That shrinks the window area allowed on a wall close to the neighbour, and a sprinklered house keeps the full amount. Second, an attached garage in an NFPA 13D house does not need heads, because the standard's own exemptions carry through. That first point matters on a rural Abbotsford or Mission lot, where response times run long and the unsprinklered version of a house can lose window area on the wall nearest the neighbour.

What an NFPA 13D system actually is

NFPA 13D is the National Fire Protection Association's standard for sprinkler systems in one- and two-family dwellings and manufactured homes. It is a lighter standard than the NFPA 13 used in commercial and multi-unit buildings, and it is the one the BC Building Code points to for houses. The design work is done by a sprinkler engineer, who lays out the heads room by room and runs hydraulic calculations to prove the water supply can deliver the flow and pressure those heads need.

The part homeowners get wrong most often is how the heads work. The home fire sprinkler leaflet the City of Burnaby publishes puts it plainly: only the sprinkler closest to the fire activates, and it is the high temperature of a fire that sets it off. Burnt toast and cigar smoke do nothing. A sprinkler head is a heat-sensitive plug, and the rest of the house stays dry, whatever films suggest. The same leaflet has two maintenance notes we repeat at handover: never turn off the main control valve, and winterize the system the same way you would winterize any domestic water line.

In Burnaby, any installation of new sprinkler heads needs a fire sprinkler permit, and the City's Fire Protection Sprinkler Permits guide lists what goes in: signed and sealed shop drawings, signed and sealed hydraulic calculations, and a Schedule B letter of assurance from the sprinkler engineer. The contractor has to hold a current Trades Qualification Certificate and a Burnaby or inter-municipal business licence. At the end, a Schedule C-B and the contractor's material and test certificate go in, and the City wants them at least five working days before the final inspection.

How the system connects to the water service

This is where the sprinkler decision reaches into the plumbing rough-in.

Burnaby allows and recommends a flow-through system for single and two-family homes instead of a conventional system with a double check valve assembly. The sprinkler piping is fed from the house water service, and a line from the most remote sprinkler head continues on to feed a tank-type toilet. Every flush pulls fresh water through the sprinkler main, so the water in those pipes never goes stagnant. That lowers the backflow hazard, which is why the City accepts a simpler backflow device on the service and drops the annual testing that a double check valve assembly would need.

The City's guide sets the details the plumber and sprinkler contractor have to coordinate: the only shutoff on the sprinkler side is the main valve at the point of entry, the domestic side gets its own shutoff just past its takeoff, no dead-leg branches to any head, and a vane-type flow alarm that trips when a head opens but stays quiet when the toilet flushes. The sprinkler piping has to be suitable for drinking water and conform to the BC Plumbing Code, since potable water lives in it. Underground piping and any backflow device need their own plumbing permits, and the City warns that a backflow device applied for late will delay the sprinkler permit.

The size of the water service is the other consequence. A sprinkler system needs a certain flow at a certain pressure at the farthest head, on top of the domestic demand the hydraulic design has to allow for. On a lot with low street pressure, the calculation can push the service to a larger diameter than the house would otherwise need. We want that number before the service is trenched, because upsizing a water service after the driveway is poured means cutting the driveway.

A sprinkler system is a plumbing decision that has to be made before there is any plumbing. Once the ceilings are closed and the service is in the ground, every option left is a worse one.

Icon Projects Team

Smoke alarms under the BC Building Code

Article 9.10.19 of the 2024 BC Building Code governs smoke alarms in houses, and it is more demanding than what most people remember from the house they grew up in.

Within a dwelling unit, there has to be at least one smoke alarm on every storey, including the basement. On any storey with bedrooms, there has to be an alarm inside each bedroom and another one between the bedrooms and the rest of that storey. If the bedrooms open off a hallway, that second alarm goes in the hallway. Alarms are mounted on or near the ceiling and installed to the CAN/ULC-S553 standard.

Power is the part that catches renovators who think a battery unit from the hardware store is enough. The code requires smoke alarms to be permanently wired to an electrical circuit, with no disconnect switch between the breaker and the alarm, and with a battery backup that can carry the alarm for at least 7 days in normal condition followed by 4 minutes of alarm if the power fails. Where more than one alarm is required in a dwelling unit, they have to be interconnected so that when one goes off, every alarm in the unit sounds. Each alarm also needs a manual silence feature that quiets it for no more than 10 minutes and then resets.

A house with a secondary suite adds a layer. The code asks for photo-electric alarms interconnected across both units and their common spaces, with the wiring arrangement tied to the fire-resistance rating of the separations between suite and main house. The code drops that cross-unit interconnection where the separations reach 45 minutes or where the building is sprinklered, which is one of the quieter arguments for sprinklering a house with a suite.

Carbon monoxide alarms

Carbon monoxide alarms live in a different part of the code, Article 9.32.4.2, and what is in the building triggers them. The article applies to a residential building that is served by or contains a fuel-burning appliance, or that contains a storage garage. A gas fireplace, a gas range, a wood stove, or an attached garage each bring the requirement in.

Where a fuel-burning appliance is inside the dwelling unit, a CO alarm goes inside each bedroom or outside each bedroom within 5 metres of the bedroom door, measured along the hallway. A room with a wood stove or other solid-fuel appliance gets its own alarm, mounted on or near the ceiling unless the manufacturer says otherwise. A suite that shares a wall or floor with a garage, or that sits next to an attic or crawl space the garage also touches, gets alarms at the bedrooms too. The alarms conform to CSA 6.19, and where the house wiring powers them there can be no disconnect switch on the circuit. In a house with a secondary suite, the CO alarms are interconnected the same way the smoke alarms are.

A heat-pump house with no gas and a detached garage may fall outside the article entirely. An attached garage is the norm on the Burnaby lots we build on, so in practice we plan CO alarms at the bedrooms on every job and treat the exception as the rare case.

Why all of it gets settled at rough-in

Every item above lands in one of two trades before the drywall goes on.

The electrical rough-in carries the smoke alarm and CO alarm circuits: the dedicated wiring with no switch on it, the interconnect conductor that links every alarm, and the box locations at each bedroom, each hallway, each storey and, where needed, the service room. We lay those out on the electrical plan alongside the lighting, because a smoke alarm and a recessed light fighting for the same ceiling spot is a detail nobody wants to resolve on a ladder.

The plumbing rough-in carries the sprinkler piping, the toilet connection at the far end of the loop, the flow switch, the backflow device and the service size. The sprinkler engineer's drawings, the plumber's layout and the framing plan all have to agree on where the pipes run, and the heads have to clear the HRV grilles, the pot lights and any ceiling feature the design calls for.

Then there is paperwork with dates on it. The sprinkler permit is separate from the building permit and needs the sealed drawings up front, and the Schedule C-B and test certificate come at the end. If either sits undone, the occupancy permit waits. Our summary of the 2024 code changes covers the edition inspectors now check against, and an alarm layout copied from an older set of drawings is worth a second look against it.

Sprinklers are the one item on this list most owners get to choose. The alarms are the floor. Get both drawn, priced and permitted before the framers close a single ceiling, and the life-safety side of the house is finished in the week the schedule planned for it.

Frequently asked questions

Does a new custom home in Burnaby need fire sprinklers?

Usually not. Under Burnaby's R1 zoning district, an automatic sprinkler system is required only when a dwelling unit is located more than 45 metres from a lot line that abuts a street. A house on a normal Burnaby lot sits well inside that distance, so sprinklers are the owner's choice. A deep lot, a panhandle lot, or a rear building on a large lot can cross the line, which is why we check it on the site plan.

Are fire sprinklers required in a new house in North Vancouver?

In the District of North Vancouver, yes, inside its fire limits areas. The District's building bylaw requires all single-family homes in those areas to be sprinklered to NFPA 13D, with each dwelling unit on its own sprinkler water supply. Confirm whether a specific lot falls inside a fire limits area with the District before design starts.

What is NFPA 13D?

NFPA 13D is the standard for installing fire sprinkler systems in one- and two-family dwellings and manufactured homes. The BC Building Code permits it for residential buildings with no more than two dwelling units, in place of the larger NFPA 13 standard used for commercial and multi-unit buildings. It is the standard a sprinkler engineer designs a house system to, and the one municipalities like Burnaby and North Vancouver reference for houses.

How does a residential fire sprinkler system connect to the water supply in Burnaby?

Burnaby allows and recommends a flow-through system for single and two-family homes. The sprinkler piping is fed from the house water service, and a line from the most remote sprinkler head continues on to feed a tank-type toilet, so fresh water moves through the sprinkler pipe every time that toilet is flushed. That reduces the backflow risk and lets the City accept a simpler backflow device instead of a double check valve assembly.

Do fire sprinklers go off from burnt toast or cigarette smoke?

No. A residential sprinkler head is triggered by the heat of a fire at that head, and only the head closest to the fire activates. A sprinkler head responds to heat and a smoke alarm responds to smoke, which is why a house needs both.

Where does the BC Building Code require smoke alarms in a house?

Article 9.10.19 of the 2024 BC Building Code requires at least one smoke alarm on every storey including the basement, one in every bedroom, and one in the hallway or space between the bedrooms and the rest of that storey. They must be mounted on or near the ceiling, permanently wired to a circuit with no disconnect switch, backed up by a battery, and interconnected so that when one sounds they all sound.

Does an all-electric home in Burnaby still need a carbon monoxide alarm?

It depends on what else is in the building. Article 9.32.4.2 of the 2024 BC Building Code applies where a residential building is served by or contains a fuel-burning appliance, or contains a storage garage. A heat-pump house with no gas appliance and no attached garage may fall outside the article. Add a gas fireplace, a gas range, or an attached garage and CO alarms are required, placed inside each bedroom or within 5 metres of each bedroom door.

Can fire sprinklers be added to a house after it is built?

They can, but it costs far more disruption than planning them in at rough-in. Sprinkler piping runs through ceilings and walls that would have to be opened, the water service may need to be upsized, and Burnaby requires a fire sprinkler permit with engineer-sealed drawings and hydraulic calculations for any new heads. On a new build, we settle sprinklers before the plumbing and electrical rough-in so none of that comes later.