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Every 2024 IRC section and the IBC as it loads, by number or topic, plus the local rules for your city. Free to search.

Detached houses, duplexes and townhouses up to 3 stories with their own exits use the IRC; every other building uses the IBC (IBC 101.2).

34 sections matching “R306” for San Antonio, TX, the 2024 IRC and IBC

  • R306.2

    Flood Hazard Areas (Including A Zones)

    • Areas with 1.5 to 3 ft waves are Coastal A Zones and follow the coastal rules.

    International Residential Code, 2024 · Chapter 3, Building PlanningRead the full text (opens UpCodes in a new tab)

  • R306.3

    Coastal High-Hazard Areas (Including V Zones and Coastal A Zones, Where Designated)

    • Areas with waves over 3 ft or high-velocity wave action are coastal high-hazard (V) zones.

    International Residential Code, 2024 · Chapter 3, Building PlanningRead the full text (opens UpCodes in a new tab)

  • R306.1.4

    Establishing the Design Flood Elevation

    • The design flood elevation is the higher of the 1% annual chance flood level and any adopted local flood map.

    International Residential Code, 2024 · Chapter 3, Building PlanningRead the full text (opens UpCodes in a new tab)

  • R306.1.6

    Protection of Mechanical, Plumbing and Electrical Systems

    • Mechanical, electrical and plumbing equipment sits at or above the required flood elevation unless built to resist floodwater, and never on breakaway walls.

    International Residential Code, 2024 · Chapter 3, Building PlanningRead the full text (opens UpCodes in a new tab)

  • R306.2.1

    Elevation Requirements

    • In A Zones the lowest floor, basement included, is at least 1 ft above base flood or at the design flood level, whichever is higher.
    • In AO shallow-flood zones, the lowest floor is the mapped depth plus 1 ft above the highest adjacent grade, or 3 ft if no depth is mapped.
    • A detached garage or shed may sit below flood level if it's one story, 600 sq ft or less, storage or parking only, anchored, vented and flood-resistant.

    International Residential Code, 2024 · Chapter 3, Building PlanningRead the full text (opens UpCodes in a new tab)

  • R306.2.2

    Enclosed Area Below Required Elevation

    • Enclosures below flood level are for parking, access or storage only, with at least 1 sq in of flood opening per sq ft of enclosed area.

    International Residential Code, 2024 · Chapter 3, Building PlanningRead the full text (opens UpCodes in a new tab)

  • R306.2.3

    Foundation Design and Construction

    • Without R404 design, plain masonry flood walls are limited to 3 ft (6 in) or 4 ft (8 in) unsupported, and reinforced 8 in walls to 8 ft.

    International Residential Code, 2024 · Chapter 3, Building PlanningRead the full text (opens UpCodes in a new tab)

  • R306.3.1

    Location and Site Preparation

    • New or substantially improved coastal buildings sit landward of mean high tide; altering dunes or mangroves needs an engineering analysis.

    International Residential Code, 2024 · Chapter 3, Building PlanningRead the full text (opens UpCodes in a new tab)

  • R306.3.2

    Elevation Requirements

    • In V and Coastal A zones, the underside of the lowest floor framing is at least 1 ft above base flood or at design flood, whichever is higher.
    • Coastal detached accessory buildings below flood level are capped at 100 sq ft, one story, storage or parking.

    International Residential Code, 2024 · Chapter 3, Building PlanningRead the full text (opens UpCodes in a new tab)

  • R306.3.3

    Foundations

    • Coastal buildings stand on anchored piles or columns designed per ASCE 24 for wave, wind and scour; Coastal A Zones may use designed stem walls.

    International Residential Code, 2024 · Chapter 3, Building PlanningRead the full text (opens UpCodes in a new tab)

  • R306.3.4

    Concrete Slabs

    • Slabs under coastal buildings are either breakaway (4 in thick at most, unreinforced, jointed 4 ft or less) or fully structural.

    International Residential Code, 2024 · Chapter 3, Building PlanningRead the full text (opens UpCodes in a new tab)

  • R306.3.5

    Walls Below Required Elevation

    • Walls below a coastal building are non-structural and either screen, lattice or breakaway at 10 to 20 psf; stronger walls need a sealed design.

    International Residential Code, 2024 · Chapter 3, Building PlanningRead the full text (opens UpCodes in a new tab)

  • R306.3.6

    Enclosed Areas Below Required Elevation

    • Enclosed space below a coastal building is for parking, access or storage only.

    International Residential Code, 2024 · Chapter 3, Building PlanningRead the full text (opens UpCodes in a new tab)

  • R306.3.7

    Stairways and Ramps

    • Stairs below coastal floor level are open, breakaway (if not egress), retractable or flood-resistant.

    International Residential Code, 2024 · Chapter 3, Building PlanningRead the full text (opens UpCodes in a new tab)

  • R306.3.8

    Decks and Porches

    • Attached coastal decks meet the elevation rule; freestanding low decks aren't walled in and must stay put or break away.

    International Residential Code, 2024 · Chapter 3, Building PlanningRead the full text (opens UpCodes in a new tab)

  • R306.1.4.2

    Determination of Impacts

    • In a riverine area without a mapped floodway, the project plus other encroachments can't raise flood levels more than 1 ft.

    International Residential Code, 2024 · Chapter 3, Building PlanningRead the full text (opens UpCodes in a new tab)

  • R306.2.2.1

    Installation of Openings

    • Each enclosed area needs at least two flood openings on different sides, with their bottoms no more than 1 ft above grade.

    International Residential Code, 2024 · Chapter 3, Building PlanningRead the full text (opens UpCodes in a new tab)

  • R306.3.6.1

    Protection of Building Envelope

    • A stair inside breakaway walls needs an R609-compliant exterior door at its top.

    International Residential Code, 2024 · Chapter 3, Building PlanningRead the full text (opens UpCodes in a new tab)

  • R401.1

    Application

    • This chapter governs foundations and foundation spaces; flood-zone foundations also follow R306, and wood foundations follow AWC PWF.
    • Prescriptive wood foundations are limited to two floors and a roof, with interior walls at most 50 ft apart; in SDC D they must be engineered.

    International Residential Code, 2024 · Chapter 4, FoundationsRead the full text (opens UpCodes in a new tab)

  • R301.2.4

    Floodplain Construction

    • Building in a flood hazard area follows R306; straddling zones takes the strictest zone, and floodways use ASCE 24.

    International Residential Code, 2024 · Chapter 3, Building PlanningRead 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.

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