Minimum areas and heights for habitable rooms, the staircases that serve them, and the shafts that light and ventilate them.
How small can a room be?
Habitable room ≥9.5 m²/2.4 m wide; kitchen ≥4.5 m²/1.8 m; bath ≥1.8 m²/1.2 m; WC ≥1.1 m²/0.9 m; toilet ≥2.3 m²/1.2 m; corridor ≥1.0 m; stairs ≥1.0 m (res); openings ≥1/6 floor area; balcony ≤1.2 m wide on ≤50% frontage.
Appendix-1 General Reg 21 — and 5 related rules below.
The rules — all 6
Room area norms
verbatim
Habitable room ≥9.5 m²/2.4 m wide; kitchen ≥4.5 m²/1.8 m; bath ≥1.8 m²/1.2 m; WC ≥1.1 m²/0.9 m; toilet ≥2.3 m²/1.2 m; corridor ≥1.0 m; stairs ≥1.0 m (res); openings ≥1/6 floor area; balcony ≤1.2 m wide on ≤50% frontage.
Appendix-1 General Reg 21· Appendix-1 (general buildings) · Appendix-7 (projects over 2,500 m²)
Habitable m2
9.5
Kitchen m2
4.5
Bath m2
1.8
Wc m2
1.1
Toilet m2
2.3
Habitable room height
verbatim
Habitable/office rooms 2.75–3.50 m floor-to-ceiling.
Appendix-1 General Reg 7· Appendix-1 (general buildings) · Appendix-7 (projects over 2,500 m²) · Appendix-8
Min m
2.75
Max m
3.5
Staircases
verbatim
Minimum 2 staircases where floor area exceeds 500 m²; at least one on an external wall opening directly outside; width 3.00 m (1.50 m per flight).
WC/baths not on open faces must open to a shaft: ≤10 m height → 1.20 m² (0.9 m min side); ≤12 m → 2.80 m² (1.2 m); ≤18 m → 4.00 m² (1.5 m); ≥24 m → 5.40 m² (1.8 m). Each flat must get ≥3 hours winter sun; kitchens/services on external walls.
Appendix-7 (2022) Reg 15(i)· Appendix-7 (projects over 2,500 m²)
When the owner selects a view direction, blocks are laid out as slabs and EVERY dwelling faces that view — living rooms and balconies to the view face, never split east/west around a central core.
Design mandate — orientation to the chosen view (owner preference)· Appendix-7 (projects over 2,500 m²) · Appendix-1 (general buildings)
Residential blocks keep the view over secondary blocks
verbatim
Commercial and public/semi-public blocks must not obstruct the outlook of any residential block. Their built height is kept below the residential block height so a residential block always sees over them; a residential block may screen a commercial/public block, never the reverse. No view overlap that hides a residential block is permitted.
Computed live by the same engine that produces the drawings — not a stored example.
Drawn square for clarity. A real tatima is not square — that is what the tracer is for.
Regime
Appendix-1 (General Building)
FAR
1.75
Setbacks (F / R / sides)
3 / 2 / 2 m
Buildable footprint
319 m²
Height cap
21 m
Storeys
3
Permissible built-up
875 m²
Parking required
9 ECS
500 m² × FAR 1.75
= 875 m² permitted.
The 319 m² footprint over
3 storeys could hold
956 m², so FAR is the
binding constraint — the height allowance is not fully usable here.
Work it out for your own plot
Risers, treads and going from your floor-to-floor height — checked against the NBC comfort rules.
