Framing Calculators quotes building code limits and lumber design values so you can plan carpentry work. It is not a building department, an engineer or a code consultant.
Model codes are adopted locally
The International Residential Code, England's Approved Document K, the National Building Code of Canada and Australia's National Construction Code are model or national documents. States, provinces, territories and cities adopt them on their own schedules and often amend them. The edition and amendments your building department enforces are the ones that apply to your project.
Spans and structural checks
The joist span calculator and the span references on this site follow the published method behind the American Wood Council span tables for uniformly loaded, simply supported sawn lumber. They do not cover point loads, notches, holes, cantilevers beyond the stated limits, engineered lumber, trusses or unusual conditions. Use the manufacturer's tables for engineered products and have a qualified professional check anything outside the simple cases.
Permits and inspections
Many stair, deck, roof and wall projects need a permit. Ask your building department before you start, follow the inspection schedule, and follow the installation instructions for every product you use.