Getting bathroom plumbing rough-in dimensions right prevents costly fixture and layout mistakes — the spacing for toilets, sinks, tubs and showers follows code and manufacturer specs. Here's a Calgary guide.
Get the Rough-In Right — It’s Cheaper Than Fixing It Later
Plumbing rough-in dimensions determine where your fixtures sit. Get them wrong and your toilet is too close to the wall, your shower drain is off-centre, or your vanity can’t be installed. Here are the correct specs for Calgary.
Toilet Rough-In Dimensions
- Standard rough-in: 12″ from finished wall to centre of drain
- Alternative: 10″ or 14″ (less common — verify your toilet model)
- Side clearance: 15″ minimum from centre of toilet to side wall or obstruction (18″ recommended per NKBA)
- Front clearance: 21″ minimum from front of toilet to facing wall (24–30″ preferred)
- Supply rough-in: 6″ above floor, 6″ to left of centre
Shower Rough-In Dimensions
- Drain: Centred in the shower floor (or per layout plan)
- Showerhead rough-in: 80″ above drain (6’8″) — standard
- Valve rough-in: 48″ above floor — standard
- Hot/cold supply: 6″ apart, centred on wall
- Curbless shower: Drain slightly higher than floor to allow linear drain slope
Vanity/Sink Rough-In
- Drain centre: 16–19″ off finished floor (matches P-trap height)
- Supply lines: 21–24″ off floor, 4″ either side of drain centre
- Shut-off valves: Below counter height, accessible
Bathtub Rough-In
- Overflow/drain: Per tub spec sheet — varies by model
- Faucet rough-in: 4″ from tub rim, 33″ from floor (standard)
- Hot/cold supply: 8″ apart (standard) or 6″ (narrow deck)
- Transfer valve: 28″ off floor
Clearances Required by Alberta Building Code
| Item | Minimum Clearance |
|---|---|
| Toilet to side wall | 15″ (centre to wall) |
| Toilet to front obstruction | 21″ |
| Shower entry clearance | 24″ minimum |
| Shower min size | 30″×30″ (32″×32″ recommended) |
| Vanity to toilet | 15″ (edge to toilet centre) |
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⚠ Estimate Disclaimer: These are only ROUGH estimates that can vary wildly. Do not take these numbers as gospel. Having a defined scope of work and exact selections will give you clarity.
Why This Matters
If your plumber rough-ins the drain 14″ from the wall instead of 12″, your standard toilet won’t fit — you’ll need a 14″ rough-in toilet (fewer options, usually more expensive). Getting rough-in dimensions right before the slab is poured saves thousands in rework.
Always Verify with Your Fixture Specs
Before rough-in, have your actual fixture specification sheets on hand. Every manufacturer has slightly different requirements. A good plumber will verify against the actual product, not just use generic dimensions.
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Frequently asked questions
The placement of water and drain lines before the walls and fixtures go in.
Typically 12 inches from the wall, with code-required clearances around the fixture.
Getting them wrong means fixtures don't fit or meet code — expensive to fix later.
Yes — our team sets the rough-in to code as part of the renovation.
Related reading: bathroom renovation guide, bathroom vanity guide, and what to expect week by week