Second-storey additions in Oshawa

Oshawa has the oldest housing of the five Durham Region, Ontario, towns along the lake, and the most older homes of any Durham municipality. Of 66,630 occupied homes in the 2021 Census, nearly a quarter date from 1960 or before. The census doesn't say how many are bungalows, but it does say an Oshawa house is more likely than not to be 45 years old or more.

A house that age was footed and framed for the load it carries now, not for another floor. So the first visit is about what's underneath. The engineer wants footing width and depth, whether the walls are concrete block or poured, and where new point loads will land. Main-floor ceiling joists usually become the new floor, and joists sized for a ceiling rarely carry a bedroom, so plan on new joists or reinforced ones. If a footing is too small, the fix is underpinning that section or a new footing under a post. Either one changes the budget, so the engineer's visit comes before a firm price.

From grade to the roof, where "grade" for a building is the average finished ground level along its front wall, per the definitions in By-law 60-94. On a gable or hip roof the top point is the average level between eaves and ridge. A flat roof is measured to its highest point, and so is a one-slope roof pitched under 20 degrees. On our reading, a lot that drops away behind the house leaves the back wall standing taller than 9.0 m without breaking the limit, because the measurement starts at the front.

That definition matters for roof shape. We rebuilt a Whitby bungalow as a two-storey house in 2023 with a single-slope roof to stop ice damming; in Oshawa, a single slope under 20 degrees counts to its top edge and uses more of the 9.0 m than a gable would.

Oshawa's 2026 rate is $15.56 per m² of new floor area, measured to the outer face of the exterior walls, under Schedule B of By-law 33-2009. A 75 m² storey is about $1,167, and a 93 m² one (roughly 1,000 sq ft) is about $1,447 (our arithmetic). Gutting the main floor at the same time adds a $160 flat fee. The by-law lets fees rise 3% each 1 January.

Plan to live elsewhere for the roof-off and framing stage. The stair, plumbing stack and ductwork all run up through the old main floor, so the trades are working inside the rooms you'd be living in. Our nearest finished second storey is West Lynde, about 6 km west in Whitby, where the kitchen and both bathrooms below were redone in the same job.