Guide 018 min read
Natural Light in Residential Design.
A plain-language guide to OBC Table 9.7.2.3 — what it requires, how to measure it, and the pitfalls that trip up most permit submissions.
OBC 2024Part 9Table 9.7.2.3
Ontario Building Code
Plain-language guides to the OBC rules behind our calculators — written for designers, builders, and anyone working through a residential permit in Ontario.
A plain-language guide to OBC Table 9.7.2.3 — what it requires, how to measure it, and the pitfalls that trip up most permit submissions.
How limiting distance and exposing building face control the size and number of windows on a house — and why fire spread is at the heart of every calculation.
How heating degree days shape climate zones, what SB-12 and SB-10 require, and how to read the assembly R-values that go onto every building permit set in Ontario.
How one window in every suite can save a life — the dimensions, operating rules, and basement-specific requirements under OBC 9.9.10.1.