How Much Does It Cost to Add a Second Floor to a Bungalow in Ottawa?

Adding a second floor is one of the most effective ways to double the living space of an Ottawa bungalow without giving up any of your lot. It's also one of the larger projects a homeowner can take on, so the first question is almost always the same: what does it actually cost? For most Ottawa bungalows, a second-storey addition runs $300 to $500 per square foot, which works out to roughly $250,000 to $500,000 or more depending on the size of the home and the complexity of the design.

Below we break down what drives that number, how to budget realistically, and where a second storey fits against other ways of adding space. If you're weighing options more broadly, our guide to the cost of home additions in Ottawa puts second-storey additions in context alongside garages, extensions, and other projects.

Second-Storey Addition Cost In Ottawa At A Glance

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What Drives The Cost Of A Second-Storey Addition

Square Footage

The single biggest factor is how much space you're adding. Most Ottawa bungalows sit on a footprint of 1,000 to 1,400 square feet, and a full second storey roughly matches that. At $300 to $500 per square foot, even modest changes in size move the total meaningfully.

Structural Reinforcement

A bungalow was not designed to carry a second floor. Before framing begins, an engineer assesses whether the existing foundation, footings, and load-bearing walls can support the added weight. Many Ottawa homes need foundation underpinning or reinforced beams, and this structural work is a major reason second storeys cost more per square foot than a ground-level extension.

Mechanical Systems

Doubling your square footage usually means your furnace, electrical panel, and plumbing stack all need to be upgraded or extended. A new staircase also has to be carved out of the existing main floor, which often triggers a partial redesign of the layout below.

Design And Finishes

Bedrooms and a hallway finished to a builder standard cost far less than a primary suite with an ensuite, walk-in closet, and custom millwork. Finishes are where budgets stretch the most, so decisions here have a large impact on the final number.

Temporary Living Costs

Because the roof comes off during a full second-storey build, most families move out for part of the project. Renting elsewhere for a few months is a real cost worth building into your budget.

Is A Second Storey Worth It In Ottawa?

For homeowners who love their neighbourhood, a second storey is often more cost-effective than buying a larger house once you account for land transfer tax, real estate commissions, and moving costs. It also lets you stay on the same lot while dramatically increasing both space and resale value, which is particularly valuable in Ottawa's established, land-constrained inner neighbourhoods where lots rarely come up for sale.

It's also worth understanding how recent zoning changes affect what you can build. See our overview of Ottawa bungalow belt zoning changes before you finalize a design.

How Long Does It Take?

A full second-storey addition typically takes 4 to 7 months from permit to completion, with larger or more complex builds running longer. Permitting alone can take several weeks in Ottawa. For a full breakdown of timelines by project type, see how long it takes to build a home addition in Ottawa.

Planning Your Second Storey With OGC

Ottawa General Contractors has helped homeowners across the city convert single-storey bungalows into full two-storey homes, handling the engineering, permits, and construction from start to finish. If you're weighing a second storey, the best first step is an honest assessment of your home's structure and a realistic, itemized budget.

Ready to explore your options? Learn more on our second floor additions in Ottawa service page, read our step-by-step guide on how to add a second story to a bungalow, or contact us today for a consultation.

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