Second-Storey Additions in Coquitlam
A second storey adds rooms on the footprint your house already has, so the yard stays where it is. Whether a Coquitlam house can take one comes down to three numbers in the City's zoning bylaw, and for most lots they now come from residential zones the City introduced in June 2025.
- 0.65floor area ratio for a house or duplex in R-1
- 3 storeyson any face, counting an exposed basement
- 11.0 mtotal height, average grade to the peak
Most Coquitlam lots moved off RS-1 in 2025
On June 9, 2025, Coquitlam Council adopted the zoning changes that put the Province's small-scale multi-unit housing legislation into effect. It created four new zones, R-1 Small-Scale Residential through R-4 Intensive Small-Scale Residential, and the first three allow up to four dwelling units on a lot. The staff report put the main rezoning step at approximately 90% of the lots affected, which moved former RS-1 and RS-3 lots, among others, into the new zones.
Not every lot moved. Lots in Transit-Oriented Areas, most lots larger than 4,050 m², and lots without municipal sewer or water connections kept their existing zoning. RS-1, RS-3 and RS-4 still exist as "legacy zones" for those lots until they are rezoned, and RS-2, renamed Rural Residential, remains as well. So an RS-1 figure from a designer or an older web page may be right for your lot, or may describe zoning your lot no longer has. Look up the current zone for your address before anyone draws a floor plan; the numbers below are for the new zones.
| Rule | R-1 | R-2 | R-3 |
|---|---|---|---|
| Minimum lot | 650 m², 18.5 m wide | 465 m², 12.5 m wide | 650 m², 18.5 m wide |
| Floor area ratio | 0.65 (1–2 units), 0.75 (3–4) | 0.75 | 0.50 |
| Lot coverage | 50% | 50% | 45% |
| Height | 3 storeys on any face and 11.0 m in all three zones | ||
R-4 works differently: it needs a lot of at least 930 m², sets its height at 9.5 m (11.0 m with a roof pitch of 3 in 12 or steeper), and requires at least three units on a lot. R-3 is the zone the bylaw describes as intended for areas where lot consolidation and rezoning to higher density are desirable, so a large investment there deserves a conversation with planning staff first.
Why going up uses density but not coverage
Coverage is measured from the outermost walls, as a share of the lot. Put a new floor on the walls you already have and that percentage does not move, which is why a second storey can fit on a lot where a rear extension would not.
Density is the limit to check first. The bylaw's definition of floor area adds up every floor, measured to the outside of the sheathing, and it explicitly includes above-grade garages. It excludes underground parking and underground storage or mechanical space; a lived-in basement is not on that list of exclusions. So the space your house already uses may have spent more of the allowance than the main floor alone suggests.
Once that number is known, the budget conversation gets real. Our breakdown of what a second storey on a Coquitlam rancher costs walks through structure, roof and mechanical line items. One correction to it: a single-family house does not need a form and character development permit in Coquitlam (see below), so budget for that fee only if your lot sits in one of the areas that still requires a permit.
Count storeys on the downhill side
Coquitlam's definition of a storey leaves out basements, but the height rule in R-1, R-2 and R-3 brings them back: a basement that projects more than 1.3 m above finished grade counts as a storey, and finished grade is taken at each exterior wall. On a sloping lot the answer can therefore be different on each face of the same house.
If the downhill face of your home already shows three levels, a full storey on top is off the table under the current rules, whatever the uphill side looks like. Height is a separate check: 11.0 m from the average building grade to the uppermost peak of a sloped roof, or to the top of the parapet if the roof is flat (under 3 in 12). A steep new roof over a raised main floor can hit that line before it runs out of storeys.
Stacking a floor on the existing walls also inherits their position. The R-1 setbacks for a house are 5.5 m at the front, 6.0 m at the rear where there is no lane, 1.2 m at interior sides and 3.0 m on a flanking street. If the design needs the upper floor to sit closer than that, you are into a variance; read how a rear setback variance works in Coquitlam before designing around one.
Which permits apply to a Coquitlam second storey
- A building permit, always. The City requires one to add floor area or alter structural components, and its minor-projects guide (dated September 2019) lists an addition or house raise as work that generally falls under Part 9 of the BC Building Code. The same guide says successful projects start with an up-to-date survey of the property by a B.C. land surveyor.
- No form and character permit for a single-family dwelling. The City says so in plain words. That changes if the project adds dwelling units: its development permit areas cover intensive residential forms such as backyard suites, duplexes, triplexes and fourplexes.
- A watercourse protection permit near a creek. It applies within 30 m of the top of bank, or top of ravine bank, of any watercourse, and within 50 m in Northeast Coquitlam. The City requires it before constructing or altering land inside that area.
- A hazard-area permit on steep slopes. The City keeps development permit areas for protecting development from hazardous conditions, with steep slopes as its own example.
- A tree cutting permit if a tree is in the way. A protected tree is 20 cm or more in diameter measured 1.4 m above the ground. Most owners may take down two a year without a permit, but on a lot with a steep slope area, a riparian area or a protective covenant, every removal needs one.
The City's own advice for owners planning new housing on their lot is to email Development Services first if the house was built before 1945, if there is a creek or a steep slope on or next to the property, or if the property is in a Transit-Oriented Area or another planning study area. The same four questions are a sensible first email before a second storey too; the last one also tells you whether your lot kept a legacy RS zone.
Designing to the 2024 seismic values
Adding a floor puts more weight, and more earthquake load, on walls that were designed to carry one storey. The BC Building Code 2024 raised the province's seismic hazard values, citing new data on past Cascadia great earthquakes and new ground-motion models among the reasons. A permit applied for on or after March 10, 2025 has to meet the whole 2024 code, seismic design included, unless the project qualifies as in-stream, meaning substantial design work was already done under the 2018 code. The Province's bulletin says those in-stream projects can keep the 2018 seismic design for permits applied for before March 8, 2027, and that the rule covers Part 9 houses as well as Part 4 buildings. A second storey designed from scratch today should be assumed to fall under the new values.
In practice that shows up as bracing: sheathing, nailing and hold-downs on the floor below. Our answer on exterior sheathing for seismic lateral bracing explains what an engineer is likely to specify, and when a design moves from prescriptive tables to engineered calculations.
The house you are building on
At the 2021 census Coquitlam had 55,945 occupied private dwellings, 19,705 of them single-detached houses. Of all dwellings, 22,465 were built between 1961 and 1990: 13,125 in 1961 to 1980 and 9,340 in 1981 to 1990. That is roughly two in five homes in the city, and the figure covers every type of dwelling, not houses alone.
Age matters here because of what comes off during the work. WorkSafeBC notes that asbestos was widely used in B.C. building materials until the early 1990s, and says plainly that you cannot tell by looking. Taking off a roof and opening ceilings to tie in a new floor is the kind of work where you want a qualified asbestos survey done before anything is disturbed. The City also suggests asking about replacement if the water, sewer and storm connections to the house are more than 30 years old, which is worth knowing before a new upstairs bathroom goes on them.
On the outside, the new floor has to meet the old one. If your walls are stucco, our answer on matching stucco on a Coquitlam addition covers the choice between a texture match and a deliberate change of material at the new floor line.
On energy, Coquitlam's Step Code page sets Step 3 for Part 9 small residential buildings from May 1, 2023. It does not say how an addition to an existing house is treated, so ask at your pre-application meeting rather than assume either way.
Port Coquitlam is a different city
Everything on this page is the City of Coquitlam's bylaw, permit process and census data. Port Coquitlam has its own city hall, its own zoning bylaw and its own permit office, and nothing above should be read as applying there. If your address is in Port Coquitlam, start with our Port Coquitlam page.
Finding a contractor for a Coquitlam second storey
We will be plain about what our directory holds. In the Vancouver Construction Network directory, seven published contractors list additions among their services and name Coquitlam in their service area; five of them have claimed their listings. Those seven are based in Vancouver, North Vancouver and Surrey rather than Coquitlam, and none of them describes itself as a second-storey specialist. The directory does have contractors based in Coquitlam, but none of them lists additions as a service. Tell us your zone, whether the downhill side shows a basement, and whether there is a creek or slope nearby, and we will say honestly whether one of them is a fit.
Planning time runs longer than building time for this kind of job; see how long a second-storey addition takes in Metro Vancouver before promising anyone a move-in date.
Describe your Coquitlam houseNeighbouring area pages: Port Moody · Burnaby · New Westminster
Where these facts come from
- City of Coquitlam Zoning Bylaw, Part 10 Low-Density Residential Zones (R-1 to R-4 lot size, floor area ratio, lot coverage, setbacks, height, storey count): coquitlam.ca/DocumentCenter/View/1174
- City of Coquitlam Zoning Bylaw, Parts 1 and 2 (definitions of floor area, storey, height, lot coverage, finished grade): coquitlam.ca/DocumentCenter/View/1166
- City of Coquitlam, Report to Council, June 9, 2025, Small-Scale Multi-Unit Housing Implementation, Bylaw 5449 (RS-1, RS-3 and RS-4 moved to Part 22 Legacy Zones; rezoning step covering approximately 90% of affected lots; exemptions for Transit-Oriented Areas, lots over 4,050 m² and unserviced lots; RS-2 renamed Rural Residential): coquitlam.ca.granicus.com, June 9, 2025 report
- City of Coquitlam, Small-Scale Multi-Unit Housing in Coquitlam (June 9, 2025 adoption; contact staff first for pre-1945 houses, creeks, steep slopes, Transit-Oriented Areas): coquitlam.ca/1361
- City of Coquitlam, Development Permits (single-family exemption from form and character; watercourse 30 m / 50 m; hazardous conditions): coquitlam.ca/254/Development-Permits
- City of Coquitlam, Tree Cutting Permit (20 cm at 1.4 m; two per year; always required on steep slope, riparian or covenant lots): coquitlam.ca/558/Tree-Cutting-Permit
- City of Coquitlam, Building Permit Application Requirements, Minor Projects (September 2019; additions and house raises, when a permit is needed, 30-year service connections): coquitlam.ca/DocumentCenter/View/3473
- Province of B.C., Information Bulletin B24-02-R, Transition period for seismic requirements in the BC Building Code 2024 (September 19, 2024): gov.bc.ca/…/b24-02-r_seismic_design_delay_period_final.pdf
- Statistics Canada, 2021 Census Profile, Coquitlam (City) (dwellings by structural type and period of construction): statcan.gc.ca census profile, Coquitlam
- WorkSafeBC, Asbestos (use in B.C. building materials until the early 1990s; cannot be identified by looking): worksafebc.com/…/asbestos
- City of Coquitlam, Energy Step Code (Step 3 for Part 9 small residential from May 1, 2023): coquitlam.ca/1078/Energy-Step-Code