There is very little mystery in a 1980s bathroom in this city. Barrie built a lot of houses between 1978 and 1998, and they were built the same way. Painswick, Holly, the Midhurst estates and almost all of Alcona in Innisfil went up in that window, and demolition day in one of them turns up the same four things.
1. Grey pipe
Poly-B supply, joined with crimped acetal fittings. It is the defining find of the era and the main reason a quote for a house of this age cannot honestly be a single fixed number. The pipe is usually intact; the fittings are the failure point, and they fail without a warning drip.
While the wall is open it is inexpensive to replace within the room. As its own project later it is a drywall job through half the house. That asymmetry is the whole argument, and it is set out in full in what Poly-B means for your quote.
2. One layer of subfloor
Tile needs a stiff floor. A lot of 1980s construction used a single layer of plywood over joists spanning near their limit, which was fine under sheet vinyl and is not fine under porcelain. The symptom before demolition is a floor that feels slightly springy at the centre of the room. The symptom after tiling, if it is ignored, is a cracked grout line that becomes a cracked tile.
Adding a layer while the floor is bare is one of the cheapest items on the job.
3. A vent that stops short
Drain venting in fast subdivision construction is the part most often shortened. What turns up is a fixture vent that was never carried where it should have been, sometimes tied in flat, sometimes simply capped inside the wall. The sign in daily use is a gurgle from the sink when the toilet flushes.
Correcting it is straightforward while the wall is open, and it is close to impossible afterwards.
4. A fan going nowhere
The bathroom fan in a house of this era is either absent, or present and ducted into the attic. In a Barrie winter that means the room’s humidity is being delivered to the coldest surface in the building, where it freezes and then stains a ceiling during the first thaw. The full explanation is in why Barrie bathroom fans wreck attics.
Why this is good news
Every one of those four is cheap to fix during a renovation and expensive or impossible afterwards. Knowing the era means the allowance can be sized honestly rather than guessed at, and it means demolition day produces photographs rather than an argument.
A 1987 house in Painswick and a 2006 house in Bradford should not carry the same allowance, and a fixed price that treats them identically is charging one of those homeowners for the other one’s risk.