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• IBC 506.2.1

  Single-occupancy buildings

  • Per-story allowable area Aa = At + (NS × If). Above three stories, total area = [At + (NS × If)] × Sa, with Sa = 3 (4 with 13R); no single floor may exceed the per-story value.

  Works withIBC 506.3

  International Building Code, 2024 · Chapter 5, General Building Heights and AreasRead the full text (opens UpCodes in a new tab)

• IBC 506.2

  Allowable area determination

  • Allowable area comes from 506.2.1, 506.2.2 and the frontage increase in 506.3, using Table 506.2 factors.
  • Unsprinklered (NS) factors, e.g. VB: B 9,000, M 9,000, A-2/A-3 6,000, E 9,500, R-1/R-2/R-4 7,000, S-1 9,000, U 5,500; R-3 is unlimited. For these groups the sprinklered one-story factor (S1) is 4 × NS and multistory (SM) is 3 × NS.

  Works withIBC 506.2.1IBC 506.2.2IBC 506.3

  International Building Code, 2024 · Chapter 5, General Building Heights and AreasRead the full text (opens UpCodes in a new tab)

Searches all 4,276 IRC 2024 sections, 5,532 IBC 2024 sections and defined terms (Chapters 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33 so far) and each city's local rules as they are added. Section numbers and titles from the International Residential Code and International Building Code, 2024 editions, copyrighted by the International Code Council; the IRC's electrical chapters (34 to 43) follow NFPA 70, the National Electrical Code. Requirements are summarized in our words (IRC Chapters 3 to 43, IBC Chapters 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33); read the full text at the link on each result. Local values come from each city's published documents.