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OBC DIVISION B · PART 9 · SECTION 9.5 — DESIGN OF AREAS, SPACES AND DOORWAYS

What are the minimum living room, dining room and kitchen sizes in Ontario?

In a typical dwelling, living areas need about 13.5 m2 (145 sq ft), dining spaces about 7 m2 (75 sq ft), and kitchens about 4.2 m2 (45 sq ft), with smaller minimums where spaces are combined.

Code reference
Part 9 sets minimum areas for spaces within dwelling units: living spaces around 13.5 m2, dining spaces around 7 m2, and kitchens around 4.2 m2, with reduced minimums permitted where functions are combined into one open space or where the dwelling has fewer bedrooms, subject to overall combined-space area rules.
OBC Division B, Subsections 9.5.4. to 9.5.6.

Paraphrased for clarity — open this provision in the BUILDAiD Library for the exact wording.

What this means in practice

Modern open-concept plans usually satisfy these limits easily because combined living/dining/kitchen spaces are assessed together with a reduced total minimum. The rules bite hardest in small secondary suites, tiny homes, and basement apartments, where designers shave every square metre. Measure to wall faces and exclude areas under stairs or with insufficient ceiling height. Check the current OBC edition carefully, as room-size minimums were adjusted in the harmonized 2024 code, and municipal zoning may impose separate, stricter unit-size rules.

Plain language

The code sets floor-area minimums so rooms are actually usable: roughly 13.5 m2 for a living room, 7 m2 for dining, and 4.2 m2 for a kitchen. Open-concept layouts get a break with smaller combined totals.

Related questions

What is the minimum bedroom size in Ontario?What is the minimum ceiling height in Ontario?What is the minimum door width between rooms in an Ontario house?

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This page is provided for general information. Building code requirements depend on your specific project, occupancy and municipality, and code editions change. Always verify requirements against the current Ontario Building Code and confirm with your local building department.