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NZ Building Code · TradesMEP Rough-in Dimensions: get the trades set out right before you line
The standard residential rough-in heights and setbacks that let the plumber, electrician and gasfitter hit the right spots before the GIB goes on.
Rough-in dimensions are the heights and setbacks for residential MEP (mechanical, electrical and plumbing) services — where the pipes, wastes and cables need to land before you line, while fixing a mistake is still cheap. Get them marked out before the GIB goes on, and the trades all hit the right spots the first time. Throughout, AFFL means Above Finished Floor Level.
Set out before you line, not after
The figures below are sensible defaults, not gospel. Two things always override them:
- The actual fixture spec sheets — a wall-hung vanity or a particular toilet pan dictates its own waste and feed positions.
- The client’s needs — a tall household means raising shower heads and mixers.
Before the lining goes on:
- Mark and photograph every rough-in.
- Coordinate clashes between the plumber, electrician and gasfitter at the same time, not one after the other.
Bathroom
- WC pan: 100mm pipe centreline 200mm from the finished wall for a back-to-wall pan, or 130–300mm depending on cistern type.
- Basin: trap centre 700mm AFFL; waste at 500–700mm depending on the basin.
- Basin taps: 1100–1200mm AFFL, with 200mm spacing between tap holes.
- Shower mixer: 1100mm AFFL (some clients want 1200mm for tall users).
- Shower head: 2100mm AFFL is ideal, and never below 1900mm.
- Bath tap: 700–750mm AFFL.
- Heated towel rail: bottom at 200mm AFFL, hardwired.
Kitchen
- Sink mixer: 1050mm AFFL — that’s above a 900mm bench plus a 150mm splashback.
- Sink waste: 350mm AFFL.
- Cooktop isolator (gas or electric): cabinet-mounted under the bench, kept accessible.
- Rangehood: 600–700mm above the cooktop.
- Power outlets: 200–250mm above bench level (1100–1150mm AFFL).
- Fridge water/ice: tap at 600mm AFFL behind the fridge.
- Dishwasher: hot and cold supply at 350mm AFFL; waste at 500mm.
Power, switches & lighting
- Power outlets, bedroom/living: 300mm AFFL standard, or 1100mm for desk areas.
- Light switches: 1000–1100mm AFFL (G1/AS1 accessibility range is 900–1300mm).
- Ceiling lights (downlights): 600–900mm from the wall for working lighting, and 1200–1500mm apart.
- Pendant lights: bottom of the pendant at 2100mm AFFL minimum over a kitchen island.
- Smoke alarms: ceiling-mounted, 300mm or more from any wall, in every bedroom and the hallway.
Plain-English guide, not advice. This page helps you understand and navigate the rules — it is general information, not design, engineering or consent advice, and it does not reproduce the copyrighted tables of NZS 3604 or any Standard. Always check the current Standard or Acceptable Solution and your BCA, and use a suitably qualified LBP, engineer or QS where it matters.
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Common questions
What does AFFL mean on a rough-in?
AFFL stands for Above Finished Floor Level. Every height in these rough-in dimensions is measured from the finished floor, so set out with the final floor build-up in mind rather than the bare slab or subfloor.
How high should a shower mixer and shower head be roughed in?
The shower mixer sits at 1100mm AFFL, with some clients wanting 1200mm for tall users. The shower head is ideally at 2100mm AFFL and never below 1900mm.
Where do kitchen power outlets and the sink mixer go?
Kitchen power outlets sit 200-250mm above bench level, which works out to 1100-1150mm AFFL. The sink mixer is at 1050mm AFFL, above a 900mm bench plus a 150mm splashback.
Where should smoke alarms be positioned?
Smoke alarms are ceiling-mounted, kept 300mm or more from any wall, and fitted in every bedroom plus the hallway.
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