Rule of thumbRecommended
Half bathroom sizing
HALF-BATH-MINDescription
Half bathrooms (powder rooms — toilet + sink) need ≥18-20 sqft. The minimum dimensions are typically 3' × 6'-3'-6" × 5'.
Why this exists
Just enough for one user to enter, use, and exit.
Categories
Bathroom
Applies to
- Room types: half_bath
Source
AIA / Ramsey-Sleeperno manifest entry
Architectural Graphic Standards (—)
Section: Residential layout chapters
Published 2024-01-01 · last verified 2026-05-09
Solver enforcement
Browsable only — the solver does not currently enforce this directive (no spec-level data to check against). This entry exists so the architect personas can cite it in conversation and the user can read what the rule says.
Related directives
- Full bathroom sizing · BATHROOM-MIN
- Half bath near public zones · HALF-BATH-NEAR-PUBLIC
- Bath not opposite kitchen / dining · BATH-NOT-OPPOSITE-DINING
- Window sill heights by use: 18" living, 24-36" bedroom, 42" kitchen, 60" bath · ROT/EXT-WINDOW-SILL-HEIGHT
- Roll-in shower readiness: blocked walls for grab bars, linear drain, slip-resistant floor, OR install at construction · ROT/EXT-AIP-ROLL-IN-SHOWER-READINESS
Last reviewed 2026-05-09.