Interior Space Planning and Functional Layout
What this domain tests
Space planning questions ask for a defensible layout: zones that match the brief, circulation that meets minimum widths, furniture placed with ergonomic clearances, and room relationships that work in daily use. Marks are lost far more often through numbers than through drawing quality.
Zoning and relationships
- Three zone families: social/public (living, dining, guest), private (bedrooms, bathrooms), service (kitchen, WC, storage, utility).
- Separate day and night zones, but keep one bathroom reachable from the social zone without crossing a bedroom.
- Kitchen–dining should be direct; a WC must not open straight onto a living or dining space; bedrooms should not open directly off the living room.
- Build the plan in stages: adjacency matrix → bubble diagram → block plan → dimensioned space plan.
Numbers to know
- Circulation: main route 1,200 mm, secondary 900 mm, minimum passage past furniture 600 mm; wheelchair turning circle Ø1,500 mm; clear door width ≥ 800 mm.
- Dining: 600 mm per person at the table edge; 750 mm table depth for two facing settings; 750–900 mm chair pull-out.
- Kitchen: work-triangle legs 1.2–2.7 m, counter depth 600 mm, worktop 850–900 mm high.
- Bedroom: double bed 1,500 × 2,000 mm; 600 mm minimum each side; 900 mm at the foot of the bed.
Worked example
A bedroom is 4.20 × 3.60 m; the door sits on the 3.60 m wall near a corner, the window is centred on the opposite 3.60 m wall. Place a 1,600 mm-wide bed with its head against the 4.20 m wall: side clearances are (4,200 − 1,600) ÷ 2 = 1,300 mm each, comfortably above 600 mm and enough for 500 mm bedside tables with walking space. The bed projects 2,000 mm across the 3.60 m direction, leaving 1,600 mm; a 600 mm wardrobe leaves 1,000 mm to open its doors (700 mm needed). The 900 mm door swing must clear the wardrobe run, so the wardrobe stops 1,000 mm off the hinge wall. Every decision is a subtraction, not an opinion.
Traps that cost marks
- Fitting furniture edge to edge instead of leaving usable clearances.
- Drawing a door swing over a wardrobe, radiator or bed.
- Blocking the window wall with tall storage, losing daylight and curtain stack.
- Mixing centimetres and millimetres on the same drawing.
- Placing the WC door onto the dining area, or a bedroom opening into the living room.