Accessibility clearances from the 2010 ADA Standards and ICC A117.1, and residential lighting levels from the IES, with the numbers behind each rule.
The Codes and Standards section explains the two rulebooks that homeowners and junior designers most often confuse: the 2010 ADA Standards for Accessible Design, which bind public accommodations and are published by the U.S. Access Board, and ICC A117.1, the ANSI standard that building codes reference for dwelling units. The dimensions depend on edition and unit category. The 2010 ADA Standards use a 30 by 48 inch clear floor space and a 60 inch turning circle; ICC A117.1-2017 generally increases new-construction dimensions to 30 by 52 inches and 67 inches, with exceptions that need separate review. The section also covers illuminance, the amount of light landing on a surface, using footcandle ranges published under Illuminating Engineering Society recommendations and the one lighting number the International Residential Code actually mandates: 1 footcandle on stair treads. Every figure carries its source and its year.
Articles in Codes and Standards
The articles in Codes and Standards are listed newest first, with the publication date and a one-sentence summary of each.
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ADA and ICC A117.1 Accessibility Clearances
Clear floor space, turning space, door widths, reach ranges, and toilet, shower, and kitchen clearances from the 2010 ADA Standards and ICC A117.1-2017.
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Residential Lighting Levels in Footcandles
IES-based footcandle ranges by room, the lumen math for typical room sizes, bulb equivalents, Kelvin and CRI, and the 1 footcandle stair rule in the IRC.