9-1B-42: IRC ONE-AND-TWO-FAMILY DWELLING BUILDING CODE AMENDMENT, ADD SECTION R314.7.5, HEAT DETECTOR WITHIN GARAGES:

   R314.7.5 Heat Detector Within Garages. A heat detector, listed and interconnected to the smoke alarms, shall be installed in all attached garages and also in detached garages that do not meet required fire separation distance and have an electrical service.

(Ord. 3-25, 2-4-2025)

9-1B-43: IRC ONE-AND-TWO-FAMILY DWELLING BUILDING CODE AMENDMENT, SECTION R315.2.2, ALTERATIONS, REPAIRS AND ADDITIONS, DELETE EXCEPTION #2:

Exception #2 is deleted from Section R315.2.2, Alterations, Repairs and Additions.

(Ord. 44-17, 12-19-2017, eff. 1-1-2018; amd. Ord. 40-20, 12-1-2020, eff. 1-1-2021; Ord. 3-25, 2-4-2025)

9-1B-44: IRC ONE-AND-TWO-FAMILY DWELLING BUILDING CODE AMENDMENT, SECTION R322.1, FLOOD-RESISTANT CONSTRUCTION, GENERAL:

   R322.1 Flood-Resistant Construction, General. All construction within flood hazard areas shall be designed and constructed in accordance with the Flood Hazard regulations of the Boise Development Code in addition to this code. Buildings and structures constructed in whole or in part in flood hazard areas, including A or V Zones and Coastal A Zones, as set forth in Table R301.2(1), and substantial improvement and repair of substantial damage of buildings and structures in flood hazard areas, shall be designed and constructed in accordance with the provisions contained

   in this section. Buildings or structures that are located in more than one flood hazard area shall comply with the provisions associated with the most restrictive flood hazard area. Buildings or structures located in whole or in part in identified floodways shall be designed and constructed in accordance with ASCE 24, where or if allowed by the Flood Hazard regulations of the Boise Development Code.

(Ord. 44-17, 12-19-2017, eff. 1-1-2018; amd. Ord. 40-20, 12-1-2020, eff. 1-1-2021)

9-1B-45: IRC ONE-AND-TWO-FAMILY DWELLING BUILDING CODE AMENDMENT, SECTION R322.1.10, AS-BUILT ELEVATION DOCUMENTATION:

   R322.1.10 As-built elevation documentation. As-built elevation documentation specified in Section R322.2 or R322.3 shall be prepared and submitted as required in accordance with the Flood Hazard regulations of the Boise Development Code.

(Ord. 40-20, 12-1-2020, eff. 1-1-2021)

9-1B-46: IRC ONE-AND-TWO-FAMILY DWELLING BUILDING CODE AMENDMENT, SECTION R322.2.1, ELEVATION REQUIREMENTS:

   R322.2.1 Elevation requirements.

      1.   Buildings and structures in flood hazard areas, including flood areas designated as Coastal A Zones, shall have the lowest floors elevated to or above the base flood elevation plus what is required in the Flood Hazard regulations of the Boise Development Code.

      2.   In areas of shallow flooding (AO Zones), buildings and structures shall have the lowest floor (including basement) elevated to a height above the highest adjacent grade of not less than the depth number specified in feet on the FIRM plus what is required in the Flood Hazard regulations of the Boise Development Code.

      3.   Basement floors that are below grade on all sides shall be elevated to or above base flood elevation plus what is required in the Flood Hazard regulations of the Boise Development Code.

      Exception: Enclosed areas below the design flood elevation, including basements with floors that are not below grade on all sides, shall meet the requirements of Section R322.2.2 and as required in the Flood Hazard regulations of the Boise Development Code.

(Ord. 40-20, 12-1-2020, eff. 1-1-2021)

9-1B-47: IRC ONE-AND-TWO-FAMILY DWELLING BUILDING CODE AMENDMENT, SECTION R322.2.2, ENCLOSED AREA BELOW DESIGN FLOOD ELEVATION, SUBPARAGRAPH 2.1:

Repeal subparagraph 2.1 of Section R322.2.1, Enclosed area below design flood elevation and replace as follows:

   2.1 The total net area of all openings shall be at least one (1) square inch for each square foot of enclosed area, or the opening shall be designed and the construction documents shall include a statement that the design and installation of the openings will provide for the equalization of hydrostatic flood forces on exterior walls by allowing the automatic entry and exit of floodwaters.

(Ord. 40-20, 12-1-2020, eff. 1-1-2021)

9-1B-48: IRC ONE-AND-TWO-FAMILY DWELLING BUILDING CODE AMENDMENT, TABLE R403.1(1) MINIMUM WIDTH AND THICKNESS FOR CONCRETE FOOTINGS FOR LIGHT-FRAME CONSTRUCTION, TABLE R403.1(2) MINIMUM WIDTH AND THICKNESS FOR CONCRETE FOOTINGS FOR LIGHT-FRAME CONSTRUCTION WITH BRICK VENEER, TABLE R403.1(3) MINIMUM WIDTH AND THICKNESS FOR CONCRETE FOOTINGS WITH CAST-IN-PLACE OR FULLY GROUTED MASONRY WALL CONSTRUCTION, AND TABLE R403.4 MINIMUM DEPTH (D) AND WIDTH (W) OF CRUSHED STONE FOOTINGS, ARE DELETED:

Table R403.1(1) Minimum Width And Thickness For Concrete Footings For Light-Frame Construction, Table R403.1(2) Minimum Width And Thickness For Concrete Footings For Light-Frame Construction With Brick Veneer, Table R403.1(3) Minimum Width And Thickness For Concrete Footings With Cast-In-Place Or Fully Grouted Masonry Wall Construction, and Table R403 Minimum Depth (D) and Width (W) Of Crushed Stone Footings, are hereby deleted.

(Ord. 40-20, 12-1-2020, eff. 1-1-2021)

9-1B-49: IRC ONE-AND-TWO-FAMILY DWELLING BUILDING CODE AMENDMENT, ADD TABLE R403.1, MINIMUM WIDTH OF CONCRETE, PRECAST, OR MASONRY FOOTINGS:

Add Table R403.1, Minimum Width Of Concrete, Precast, Or Masonry Footings as follows:

   TABLE R403.1

   MINIMUM WIDTH OF CONCRETE, PRECAST, OR MASONRY FOOTINGS (inches)a

	LOAD-BEARING VALUE OF SOIL (psf)
	1,500	2,000	3,000	4,000
Conventional light-frame construction
1-Story	12	12	12	12
2-Story	15	12	12	12
3-Story	23	17	12	12
4-inch brick veneer over light-frame or 8-inch hollow concrete masonry
1-Story	12	12	12	12
2-Story	21	16	12	12
3-Story	32	24	16	12
8-inch solid or fully grouted masonry
1-Story	16	12	12	12
2-Story	29	21	14	12
3-Story	42	32	21	16

 

   For SI: 1 inch = 25.4mm, 1 pound per square foot = 0.0479 kPa.

   a.   Where minimum footing width is twelve (12) inches, use of a single wythe of solid or fully grouted twelve (12) inch nominal concrete masonry units is permitted.

(Ord. 40-20, 12-1-2020, eff. 1-1-2021)