Bathroom renovation

A bathroom is a small room with every trade in it. Two square metres of floor can involve demolition, framing, plumbing, electrical, ventilation, waterproofing, tiling, glass and paint, and the order is unforgiving. Most bathroom failures in this city are one of two things: waterproofing done as an afterthought, or a fan that vents into the attic.

Step one: decide whether the plumbing is moving. Keeping the toilet, sink and tub where they are makes this a finishes job with no permit in most cases. Moving the toilet drain, converting a tub to a curbless shower, or adding a second bathroom means new drainage, and that means a permit and an inspection. Plumbing is a compulsory trade in Ontario, so whoever does it should hold a certificate of qualification.

Step two: strip to the studs and look. In Ottawa the usual finds are a rotten subfloor at the toilet flange, a joist notched by a previous plumber, and old galvanised supply lines that crumble when moved. A gut bathroom in a pre-war house in Sandy Hill or the Glebe should be budgeted with a real contingency, because the wall cavity is where the surprises live.

Step three: rough-in and the fan. New supply and drain lines go in, along with the electrical: a dedicated circuit, GFCI protection at the receptacle and an exhaust fan ducted to the outside. That last point matters here more than almost anywhere. A fan discharging into a cold attic in an Ottawa January condenses inside the duct and drips back, and the result is a mould problem in the ceiling within two winters. The duct should be insulated, sloped and terminate at a proper exterior hood.

Step four: waterproofing. This is the step that decides whether the room lasts. A shower needs a continuous waterproof layer, whether that is a sheet membrane, a liquid membrane or a foam board system, taken up the walls and sealed at every corner and penetration. Cement board alone is not waterproofing. A proper shower gets a flood test before any tile goes on, and if a contractor does not want to do one, that tells you something.

Step five: tile, fixtures and glass. Tile, grout, then fixtures, then the glass, which is measured after the tile is set and typically takes one to two weeks to fabricate. That glass lead time is the reason a bathroom often sits ninety per cent finished for a fortnight.

How long it takes. A cosmetic refresh keeping all fixtures in place is one to two weeks. A full gut in the same footprint is three to four weeks, plus the glass. Moving plumbing, converting to a curbless shower, or adding a bathroom where there was none is four to six weeks including inspections. A basement bathroom is longer again, because the drain is broken into the floor slab and inspected before the slab is closed.

What it costs in Ottawa in 2026. Indicative ranges. A bathroom renovation commonly runs $8,000 to $30,000, split roughly as $8,000 to $15,000 for a cosmetic update and $15,000 to $30,000 for a full addition with plumbing (HomeStars, Ottawa basement renovation costs 2026). A main-floor or ensuite gut with a tiled curbless shower, heated floor and frameless glass sits at the upper end and beyond. What moves the number: whether drainage moves, tile size and pattern, whether the shower is a base or a tiled pan, frameless glass, and heated floor. Add 13 per cent HST, which is not rebatable on renovation work (CRA RC4028).

What makes an Ottawa bathroom different. Winter humidity and the drying season. Houses here run with the heat on for five or six months, which makes a bathroom the one room producing serious moisture in an otherwise very dry building. Undersized or badly ducted ventilation shows up fast as peeling paint, black grout and mould at the ceiling perimeter. The second factor is the age split in the stock: pre-war houses inside the Greenbelt with 75 mm waste stacks and no vent for a second fixture, against 1990s and later suburbs where the plumbing is modern and the room size is the only constraint. Third, in basements, Ottawa's protective plumbing programs exist because sewer backup is a real risk here, so a new basement bathroom is the right moment to ask about a backwater valve.

Who should do the work, and what protects you. There is no licence for a bathroom renovator in Ontario. The plumbing and the electrical are compulsory trades and do carry certificates, and electrical work needs an ESA notification and inspection. Structural changes, such as cutting joists for a curbless shower drain, should have a professional engineer behind them (PEO directory). Check WSIB status, which is compulsory in construction and whose occupant-retained exemption does not extend to subcontractors (WSIB). Tarion does not apply to a renovation (Tarion exclusions), so the contractor's written warranty, the permit and inspections, and the ten per cent statutory holdback are your protection (Construction Act holdback in 2026).

What to ask before you hire. Is the drainage moving, and does that need a permit. Who does the plumbing and the electrical, and can I see the certificates. What waterproofing system are you using, and will you flood test the shower pan. Where does the exhaust fan terminate, and is the duct insulated. Is the glass measured after tiling, and what is its lead time. What is the tile allowance. What is the written warranty on the waterproofing specifically, and for how long.