Does Ontario's Building Code require a Level 4 drywall finish?

Ontario's Building Code does not mention finish levels at all. The six-level scale comes from the Gypsum Association's GA-214 guide, which is an industry recommendation, not a legal or Code requirement.

GA-214 describes the levels this way: Level 0 means no taping (temporary construction or where decoration is undecided); Level 1 is tape set in compound; Level 2 adds a wipe coat and one coat on fasteners; Level 3 adds one more coat on joints and two on fasteners; Level 4 adds two more coats on joints, one on interior angles, and three on fasteners and accessories; Level 5 is Level 4 plus a thin skim coat over the entire surface. The guide lists Level 4 for flat paints and light textures, and notes that the guide does not recommend non-flat or dark paints on a Level 4 surface. It lists Level 5 for gloss or sheen paints, dark paints, and critical lighting conditions.

Because finish levels are an industry recommendation and not a Code or legal standard, there is no inspector who will measure coats or fail a wall for being Level 3 instead of Level 4. What matters practically is that you and the contractor agree in writing on which level you want before work begins. Name the level in the quote so there is no dispute at the end about how smooth the surface should be, how many coats were included, and whether primer and paint are part of the scope or separate.

A few things worth confirming in writing before the job starts: the finish level by number, the number of coats of compound on flat joints and on fasteners, whether sanding between coats is included, and whether primer is part of the contract. If you are planning a dark or high-sheen paint, ask the contractor what level they are quoting and whether a skim coat is included, because the guide's own language flags that surface differences become visible under those finishes.

Before you sign, ask the contractor to put the warranty terms in writing: what defects are covered, how long the coverage runs, and whether it carries over to a future buyer of the home.