How much should I budget for a second-storey addition on my Ottawa bungalow?

Adding a second storey to an Ottawa bungalow is one of the most transformative renovations you can take on, and it is a major investment. As broad perspective only, a full second floor can range from roughly $200,000 to $450,000 or more depending on size, structure and finishes. Treat that as a frame for planning, not a quote.

The first cost driver is structural assessment. Many bungalows were not designed to carry a second floor. A structural engineer evaluates your foundation, footings and load-bearing walls and tells you what reinforcement is needed, which might include beams, columns or footing upgrades. This step is essential before anyone can price the project properly. Older block foundations may need more work than poured concrete ones, but only the engineer can say for your house.

The roof comes off. Removing the existing roof and framing new walls, floor and roof is a large share of the budget. Your home is open to the weather during this phase, so ask each contractor how they will protect the house from rain and snow and how long it will be exposed.

Mechanical systems sized for one storey often need attention. Ask for a heat-loss calculation to determine whether your furnace and ductwork can serve the new floor, and have an electrician assess whether your panel has capacity. Electrical work needs an ESA notification and is done by an ESA-licensed electrical contractor; gas work is done by a TSSA-certified gas technician.

The Ontario Building Code governs stairs, fire protection, egress, structure and energy efficiency. Your designer will lay out a code-compliant staircase, which takes real floor area on both levels, so plan for it early.

Exterior finishing is easy to underestimate. A new storey changes the whole look of the house, and you may decide to re-clad the entire exterior for a consistent appearance. Get that priced as a separate option.

Soft costs include drawings, engineering and the building permit. Under the City's 2026 schedule, additions are charged $12.75 per $1,000 of construction value, so a $300,000 valuation would be about $3,825. The City confirms how your project is valued.

Hold a meaningful contingency, because opening an older bungalow often reveals outdated wiring, poor insulation or damaged framing. Ask contractors what surprises they price for and how changes are handled. You can browse addition contractors in the Ottawa Construction Network directory at justynrookcontracting.com and compare itemized quotes.

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Looking for experienced contractors? The Ottawa Construction Network connects homeowners with qualified professionals:

• Justyn Rook Contracting
• JC Carpentry
• Leeds Property Maintenance
• The Granite shop
• Transitions Renovations