Second-storey additions in Whitby

From the average level of the finished ground at the front of the house. On a flat roof it's measured to the highest point; on a gable, hip or gambrel roof, to the midpoint between the eaves and the ridge. Both by-laws, 1784 and Downtown's 2585, use that wording, and both set 8.5 m for a detached house in their standard residential zones. That has two effects: a lot that falls away toward the back gains nothing, because the front grade is the base. And a steeper roof can carry its ridge well above 8.5 m, since only the midpoint counts.

The exception helps older houses. Schedule A of By-law 1784 lets a building that existed before By-law 3465-94 passed reach 9.5 m in its R1, R2 and R3 zones. Newer zones and site-specific exceptions set their own heights, so we read the clause for your lot before the designer draws a roof.

In several of Whitby's newer residential zones, the standards tighten the moment a house passes one storey:

Note: base zone standards only; exceptions inside each zone can differ, and these are not the R1 to R3 figures.

In R1A* and R2A* the side yards tighten as well: the ground floor can sit 1.0 m from the side lot line but a second-storey wall needs 1.75 m. Downtown under By-law 2585 it's 1.2 m below and 2.0 m beside a second storey. A bungalow built tight to its side yard can't just stack walls on its own; the upper floor steps in, or we ask the Committee of Adjustment for a variance.

Most of Whitby is post-1981, so the pool is smaller than in Oshawa. Still, the census counts 3,810 homes from 1960 or before and 7,700 from 1961 to 1980. The census gives no split by house type within those eras, and no streets. Before design, an engineer checks whether the footings and bearing walls can take a second floor; sometimes they need reinforcing, and that changes the budget more than anything upstairs.

Once the roof comes off, the house is open to the weather until the new floor is framed and closed in, and most families move out for that stretch at least. The closest second storey we've finished is here in town: West Lynde, a Whitby bungalow we took to two storeys, about 800 sq ft upstairs plus a new kitchen and bathrooms below, in about 4.5 months on site. Greenwood, roughly 40 km west in Toronto, got a new top floor with a primary suite, a wet room with a skylight and a den onto a balcony, in 10 months including permit and design.