Calculators
Check clear opening width, height, sill height, and net area for bedrooms and basement sleeping rooms. Live diagram updates as you type.
Check rise, run, headroom, handrail height, and stair width against IRC 2021 residential building code requirements.
Verify minimum ceiling heights for habitable rooms, hallways, bathrooms, and basements — including sloped ceiling compliance.
Allowable joist spans from IRC 2021 Table R507.5 for 4 lumber species groups, 3 spacings, and all joist sizes. Live plan and cross-section diagrams.
Build a wall assembly with dropdowns and get an instant IECC 2021 climate zone pass/fail. Covers basements, above-grade walls, attics, and floors.
Code Guides & Articles
Room-by-room minimums, sloped ceiling rules, beam and duct exceptions, and common inspection failures.
Every code requirement before you finish a basement: egress, ceiling height, stair, insulation, smoke alarms, and permits.
Minimum clear opening dimensions, sill height limits, window well requirements, and the most common compliance failures.
Complete IRC stair code reference including the uniformity rule, Blondel comfort formula, and common stair failures.
How to read IRC span tables, species grade groups, spacing options, and what to do when your span exceeds the maximum.
Why use these tools?
Building code requirements exist for safety — but the code itself is written in legal language that’s hard to parse on a job site. These calculators pull out the numbers that matter, let you enter your measurements, and give you an instant, readable pass/fail result against IRC 2021.
Every tool references the specific IRC section so you know exactly what you’re checking. Results are for reference — always confirm with your local AHJ before finalizing any design.