Architectural Dimensions Reference

Overview

Authoritative dimensional standards for AI agents generating or validating 3D/2D architectural models. All dimensions follow international best practices and common building codes (ISO, IBC, Eurocode). All values are in meters (m) unless stated otherwise.

Instructions

When generating or validating any building model, apply these dimensional standards in order:

1. Ceiling Heights

Space Type	Minimum	Standard	Luxury
Residential habitable room	2.4 m	2.7 m	3.0 m
Residential corridor/bathroom	2.1 m	2.4 m	2.7 m
Commercial office	2.7 m	3.0-3.6 m	4.0 m
Retail/showroom	3.5 m	4.0-5.0 m	6.0 m
Industrial/warehouse	4.5 m	6.0-8.0 m	12.0 m+

Never generate a habitable room with ceiling height < 2.4 m. Structural floor-to-floor height = ceiling height + 0.3-0.4 m for slab thickness.

2. Wall Thicknesses

Wall Type	Thickness
Interior partition (non-load-bearing)	0.10-0.15 m
Interior load-bearing	0.20 m minimum
Exterior wall (timber/light frame)	0.14-0.20 m
Exterior wall (masonry)	0.20-0.35 m
Exterior wall (reinforced concrete)	0.20-0.40 m

3. Doors

Door Type	Width	Height
Standard interior	0.900 m	2.100 m
Bathroom/WC	0.800 m	2.100 m
Main entry/exterior	0.900-1.000 m	2.100-2.400 m
Double door (pair)	1.200-1.800 m	2.100 m
Accessible (wheelchair)	0.900 m min	2.100 m

Door frame opening = leaf width + 100 mm each side. Minimum 100 mm clearance from door edge to adjacent wall corner. Door sill height is always 0 (at floor level).

4. Windows

Window Type	Sill Height	Window Height
Standard residential	0.900 m	1.200-1.500 m
Low sill (living room)	0.300-0.600 m	1.500-1.800 m
Floor-to-ceiling	0.100 m	ceiling height - 0.2 m
High window (bathroom)	1.500-1.800 m	0.400-0.600 m

Every habitable room must have at least one window. Minimum window area >= 10% of floor area. Window head height should align with door head height (2.100-2.400 m).

5. Stairs

Parameter	Minimum	Ideal	Maximum
Riser height	0.150 m	0.175 m	0.190 m
Tread depth	0.250 m	0.280 m	0.350 m
Stair width (residential)	0.900 m	1.000 m	--
Headroom	2.000 m	2.100 m	--

Comfort rule: 2R + T = 600-630 mm. Number of risers = ceiling height / riser height (round to integer).

6. Room Sizes (Residential)

Room	Minimum	Typical	Generous
Bedroom (single)	7.2 m2	10.5 m2	14 m2
Bedroom (master)	10.5 m2	18 m2	27.5 m2
Bathroom (full)	3.15 m2	5 m2	8.75 m2
Kitchen	7.2 m2	12 m2	20 m2
Living room	15.75 m2	27 m2	42 m2
Corridor/hallway	0.9 m wide	1.0-1.2 m	1.5 m

7. Human Scale Reference

Reference	Dimension
Average adult height	1.75 m
Eye level (standing)	1.65 m
Counter height (kitchen)	0.90 m
Dining table height	0.73-0.76 m
Desk height	0.72-0.75 m
Seat height (chair)	0.43-0.46 m
Wheelchair width	0.70 m, turn radius 1.50 m

8. Default Values for Code Generation

const DEFAULTS = {
  ceilingHeight: 2.7,
  wallThicknessInterior: 0.10,
  wallThicknessExterior: 0.20,
  slabThickness: 0.25,
  floorToFloor: 3.0,
  doorWidth: 0.9,
  doorHeight: 2.1,
  windowSillHeight: 0.9,
  windowHeight: 1.2,
} as const;

9. Validation Checks

Before finalizing any model, verify:

Check	Expected Range
Floor-to-floor height	2.7-4.0 m (residential 3.0 m typical)
Building footprint density	30-60% of site for residential
Window-to-wall ratio	15-40% (residential), 40-80% (commercial)
Circulation area ratio	15-25% of total floor area
Bedrooms vs bathrooms	1 bathroom per 2 bedrooms minimum

Hard errors to flag: ceiling height < 2.1 m, exterior wall < 0.14 m thick, door width < 0.7 m, door height < 1.9 m, corridor width < 0.9 m, habitable room without window, no exterior exit door on any level.

Examples

Example 1: Validate a Residential Floor Plan

Given a 3-bedroom apartment at 85 m2:

• Ceiling height: 2.7 m (standard residential)
• Exterior walls: 0.20 m (masonry default)
• Interior partitions: 0.10 m
• Master bedroom: 14 m2 with 1.2 m x 1.2 m window at 0.9 m sill -- passes minimum 10.5 m2, has window
• Kitchen: 12 m2 with 1.0 m x 1.2 m window -- passes minimum 7.2 m2
• Corridor: 1.0 m wide -- passes minimum 0.9 m
• All doors: 0.9 m x 2.1 m standard, bathroom doors 0.8 m x 2.1 m
• Entry door: 1.0 m x 2.1 m on exterior wall
• Result: all checks pass

Example 2: Calculate Stair Geometry for 2.7 m Ceiling

• Target riser: 0.175 m, tread: 0.280 m
• Number of risers: 2700 / 175 = 15.4, round to 16
• Adjusted riser: 2700 / 16 = 168.75 mm (within 150-190 range)
• Comfort check: 2(168.75) + 280 = 617.5 mm (within 600-630)
• Number of treads: 16 - 1 = 15
• Horizontal run: 15 x 0.280 = 4.200 m
• Stair width: 1.0 m (residential standard)
• Headroom clearance: 2.1 m minimum verified

Guidelines

• Always use meters as the base unit for all dimensions
• When in doubt between minimum and standard values, use standard
• Exterior walls default to 0.20 m unless project specifies otherwise
• Interior partitions default to 0.10 m
• Ceiling height defaults to 2.7 m for residential
• Every habitable room must have natural light (window area >= 10% of floor area)
• Validate all openings fit within their host wall with 100 mm edge clearance
• For accessibility compliance, use 0.900 m minimum door width and 1.200 m corridor width
• Cross-reference room dimensions against both minimum area and minimum width requirements