Ottawa is a city built on bungalows. Tens of thousands of them across Alta Vista, Nepean, Orleans, and the older parts of Kanata. The owners are usually couples who bought 8 to 25 years ago, the family has grown, the basement is finished, and they need more bedrooms without leaving the neighbourhood.
Adding a second storey is the answer that keeps the lot, the schools, and the equity. The question is which style of second storey, because the wrong one fights the existing architecture and ages the house badly. Here are the five second-storey approaches that consistently work on Ottawa bungalows, with the structural and zoning realities behind each one.
1. The full second storey (entire footprint)
Best ford7ae87f">Best ford7ae87f">Best ford7ae87f">Best ford7ae87f">Best for: original bungalows on lots that can absorb the height. Cost drivers6ac">Cost drivers6ac">Cost drivers6ac">Cost drivers6ac">Cost drivers: structural reinforcement to carry the new floor and roof, 1,200 to 1,600 sq ft of new second floor, full removal of the existing roof.
Removing the existing roof and adding a complete second storey across the whole footprint is the cleanest result. The house gets 3 to 4 new bedrooms upstairs, the original main floor becomes the living and entertaining floor, and the front elevation reads as a proper two-storey home.
The structural work is the major budget item. The existing main-floor walls have to support the new floor and roof loads, which usually means new beams in the basement, new posts to the footings, and sometimes underpinning of the existing foundation if the original footings were undersized for two-storey loads. The structural engineer's letter is non-negotiable, and it is a line every quote for this style should name explicitly.
Zoning matters. Most R1 zones in Ottawa allow up to 11 metres or 9 metres of building height depending on the by-law section, but the maximum lot coverage and setbacks limit which existing footprints can take a full second floor. We always run a feasibility check against the lot before we quote, which is what our free 48-hour lot review delivers.
2. The partial second storey (rear half or one side)
Best for: bungalows with strong front elevations worth preserving. Cost drivers: 600 to 1,000 sq ft of new second floor, a smaller structural intervention since half the existing roof stays, the old-to-new roof connection.
The partial second storey adds new floor area over the rear half of the bungalow, leaving the front roof and elevation intact. The result is a 1.5-storey reading from the street, with the new floor invisible from the curb but full-height from behind.
This style preserves heritage character in older Glebe and Westboro neighbourhoods where Ottawa's heritage permit committees push back on full second-storey additions. It also costs about 35% less because half the existing roof stays and the structural intervention is smaller.
The challenge is the connection between the old and new roof. Done well, the transition reads as intentional. Done poorly, the house looks like an old bungalow with a box bolted to the back.
3. The dormer-driven 1.5 storey
Best for: existing bungalows with steep gable roofs and useable attic volume. Cost drivers: new dormers and a structural ridge beam, attic finishing, lighter structural work than a full lift.
Instead of removing the roof entirely, this style adds large shed dormers or gable dormers to the existing roof and finishes the attic as living space. The exterior keeps the bungalow silhouette, the interior gains 800 to 1,100 square feet of new floor area at second-storey level.
The structural work is lighter than a full lift, but the existing roof framing has to be analyzed. Most 1950s and 1960s Ottawa bungalows used 2x6 rafters at 24-inch centres with no engineered ridge. Adding dormers means installing a structural ridge beam (often 9.5-inch LVL or PSL), new collar ties, and reinforcing the rafters that carry the dormer loads.
This style is what we recommend for clients who want the bedroom count of a second storey but cannot afford the full lift. It also avoids the 4-month "no roof on the house" exposure window that a full lift creates.
4. The pop-top (raised existing roof)
Best for: bungalows with low ceilings and useable existing attic. Cost drivers: the specialized roof lift, new second-floor wall plate, framing the new floor inside the gained height.
The pop-top raises the existing roof structure on new walls instead of demolishing it. Hydraulic jacks lift the entire roof assembly 8 to 10 feet, then a new second-floor wall plate is built on top of the existing main-floor walls, the roof is set down on the new walls, and the second floor is framed inside the new height.
The advantage is preserving the roof, which means saving the rafters, the sheathing, the existing shingles (sometimes), and not exposing the home to weather during construction. The disadvantage is the lift itself is dramatic, the engineering is specialized, and the roof has to be in good enough condition to be worth saving.
This style shines on bungalows where the existing roof is recent (less than 8 years old) and the homeowner does not want to lose 25-year shingles by tearing them off. It is rarely the cheapest option but often the fastest.
5. The split-level second storey
Best for: bungalows with attached garages or split-level layouts already. Cost drivers: a half-level addition over the garage, simpler structure than a full lift since the garage walls already carry load.
On a bungalow with an attached garage, the split-level second storey adds a half-flight of stairs above the garage to a new master suite or two bedrooms. The new floor is half a level above the main floor, which is shorter than a full second-storey lift and avoids the structural complexity of supporting full second-floor loads on the original walls.
This style works particularly well on Orleans and Barrhaven bungalows from the 1990s and 2000s with two-car garages. The garage walls already have foundation that can support a second-floor load, the staircase volume already exists at the front door landing, and the addition reads as if it had always been part of the house.
Zoning, height, and the by-law that controls everything
Ottawa's Comprehensive Zoning By-law 2008-250 governs almost every second-storey addition. The key sections are maximum building height (typically 8 to 11 metres in residential zones), maximum lot coverage, and setbacks from property lines. Your existing bungalow may already exceed lot coverage as a legal non-conforming structure, in which case any addition triggers a review. We run every second-storey project through the by-law before we issue a quote. About one in eight projects requires a Minor Variance application, which adds 4 to 8 weeks plus the City's application fees but is usually approved when the case is presented properly. For more on how this works see our Ottawa home additions page.
Living through it: stay or move out?
The most-asked client question on second-storey additions is whether the family can stay in the house during construction.
The honest answer depends on the style. Full second-storey lifts mean 8 to 14 weeks of "no roof and exposed framing," during which the family must move out. Partial additions over the rear can sometimes be staged so the front of the house stays liveable, but kitchens and bathrooms often go offline mid-project. Pop-tops have a 1-week intense exposure window when the roof is lifted but daily life continues either side. Dormer additions are the most liveable, with most rooms staying available throughout.
Plan a 4 to 6 week rental window minimum on most second-storey projects. Budget for the rental period and the moving costs in and out, and include those figures in the project budget from day one. The renovations that go sideways are the ones where the family did not budget for displacement.
Schedule, start to finish
- Design and BCIN drawings: 6 to 10 weeks
- Structural engineering letter: 2 to 4 weeks (parallel with design)
- Permit submission to MyServiceOttawa: 1 day to submit, 6 to 14 weeks for review and issue depending on complexity
- Construction: 16 to 28 weeks depending on style and weather
- Total project timeline: 8 to 13 months from first design meeting to move-back-in
The clients who think they will start in March and be done by Christmas usually break ground in July and finish in May the following year. Plan accordingly.
The right second-storey addition makes the bungalow look like it always wanted to be a two-storey. The wrong addition makes the bungalow look like a hat sitting on it.
What to ask the contractor
- Has the structural engineer been retained? Whose? What is their letter going to cover?
- Has the lot been confirmed against By-law 2008-250 for height, coverage, and setbacks?
- Is the BCIN designer named and stamping the architectural drawings?
- What is the weather exposure plan during the open-roof window?
- Is the displacement budget separate from the construction budget?
- What does the warranty cover specifically? Look for the 10-year structural component, not just 1-year workmanship.
Get clear answers in writing before any deposit. Second-storey additions are the highest-stakes residential project we do. They reward homeowners who plan carefully and punish ones who rush.