CHAPTER 3-8: INTERNATIONAL RESIDENTIAL CODE FOR ONE- AND TWO-FAMILY DWELLINGS
SECTIONS:
3-8-1: ADOPTION OF THE INTERNATIONAL RESIDENTIAL CODE FOR ONE- AND TWO-FAMILY DWELLINGS:
3-8-1 ADOPTION OF THE INTERNATIONAL RESIDENTIAL CODE FOR ONE- AND TWO-FAMILY DWELLINGS:
There is hereby adopted by reference, that certain document known as the "International Residential Code for One- and Two-Family Dwellings, 2024 Edition," including Appendix BF, as published by the International Code Council. Said document is hereby amended and adopted as the "International Residential Code for One- and Two-Family Dwellings" for regulating and governing the conditions and maintenance of all property, buildings and structures; by providing the standards for supplied utilities and facilities and other physical things and conditions essential to ensure that structures are safe, sanitary and fit for occupation and use; and the condemnation of buildings and structures unfit for human occupancy and use and the demolition of such structures as herein provided; providing for the issuance of permits and collection of fees therefor; and each and all regulations, provisions, penalties, conditions, and terms of the various technical codes and ordinances. Providing procedures for enforcement thereof; providing the severability of each and all conditions and terms of the "International Residential Code for One- and Two- Family Dwellings" are hereby referred to, adopted, and made as part hereof as set forth herein, excepting such portions as are herein deleted, modified or amended. (Ord. 2025-1924, 11-18-2025)
3-8-2 AMENDMENTS:
That certain document entitled the "International Residential Code for One- and Two-Family Dwellings," which document amends and supersedes certain designated sections of the "International Residential Code for One- and Two- Family Dwellings, 2024 Edition," including Appendix BF as published by the International Code Council, and was made a public record by Resolution No. 2025-1958, is hereby adopted by this reference and amends and replaces the existing chapter and Sections 3-8-1 and 3-8-2 of the Prescott City Code.
CHAPTER 1 - SCOPE AND ADMINISTRATION
SECTION R101 SCOPE AND GENERAL REQUIREMENTS
SECTION R101.1 Title is deleted in its entirety and revised to read as follows:
R101.1 - Title. These regulations shall be known as the “International Residential Code for One- and Two- Family Dwellings”, herein referred to as “this Code”
SECTION R101.2 Scope is amended as follows:
SECTION R101.2 Scope The provisions of this code shall apply to the construction, alteration, movement, enlargement, replacement, repair, equipment, use and occupancy, location, removal and demolition of detached one- and two-family dwellings and townhouses not more than three stories above grade plane in height with a separate means of egress and their accessory structures not more than three stories above grade plane in height.
Exception: The following shall be permitted to be constructed in accordance with this code where provided with an automatic sprinkler system as required by the “International Fire Code” as adopted and amended by The City of Prescott.:
1. Live/work units located in townhouses and complying with the requirements of Section 508.5 of the International Building Code.
2. Owner-occupied lodging houses with five or fewer guestrooms.
3. A care facility with five or fewer persons receiving custodial care within a dwelling unit.
4. A care facility with five or fewer persons receiving medical care within a dwelling unit.
5. A day care facility for five or fewer persons of any age receiving care within a dwelling unit.
SECTION 102 through 116 is hereby deleted and replaced with the requirements of the “International Building Code” SECTION 102 through 116, as adopted and as may be amended from time to time.
CHAPTER 3 - BUILDING PLANNING
SECTION R301 DESIGN CRITERIA
TABLE R301.2 Climatic and Geographic Design Criteria, is hereby amended to read as follows:
Table 301.2 Climatic and Geographic Design Criteria.
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GROUND SNOW LOADo: |
Per https://ascehazardtool.org/ for IRC Building |
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WIND DESIGN: |
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Speed: |
105 mph, 3 second gust |
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SEISMIC DESIGN CATEGORY: |
C |
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SUBJECT TO DAMAGE FROM: |
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Weathering: |
Negligible |
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Frost Line Depth: |
18 inches (457.2 mm) |
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Termite: |
Moderate |
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ICE SHIELD UNDERLAYMENT: |
No |
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FLOOD HAZARDS: |
See Prescott City Code Title XIII |
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AIR FREEZING INDEX: |
194 |
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MEAN ANNUAL TEMP: |
53 degrees F |
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MANUAL J DESIGN CRITERIAn: |
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Climate Designation |
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4B Mixed-Dry |
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Elevation |
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5,510 feet |
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Outdoor winter design dry-bulb temperature |
16 degrees F |
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n. The jurisdiction shall fill in these sections of the table to establish the design criteria using Table 1a or 1b from ACCA Manual J, 8th Edition, for HVAC system design, the criteria shall be from ACCA Manual J, Table 1B for Arizona, Prescott or Prescott, Love field or from ASHREA 2021 Prescott Love Field, AZ.
o. The jurisdiction shall fill in this section of the allowable stress design table using the Ground Snow Loads Per ASCE 7-22 Hazard tool located at https://ascehazardtool.org/ for IRC Buildings.
SECTION R309.1 TOWNHOUSE AUTOMATIC SPRINKLER SYSTEM
SECTION R309.1 Townhouse automatic sprinkler systems is hereby amended to read as follows:
R309.1 Townhouse automatic sprinkler systems. An automatic sprinkler system shall be installed in townhouses as required by the "International Fire Code" as adopted and amended by The City of Prescott.
Exception: An automatic sprinkler system shall not be required where additions or alterations are made to existing townhouses that do not have an automatic sprinkler system installed.
SECTION R309.1.1 Design and Installation is hereby amended to read as follows:
R309.1.1 Design and installation. Automatic sprinkler systems shall be designed and installed in accordance with as required by the “International Fire Code” as adopted and amended by The City of Prescott.
SECTION R309.2 ONE- and TWO-FAMILY DWELLINGS AUTOMATIC SPRINKLER SYSTEM
SECTION R309.2 One- and two-family dwellings automatic sprinkler systems is hereby amended to read as follows:
R309.2 One- and two-family dwellings automatic sprinkler systems.
An automatic sprinkler system shall be installed in one- and two-family dwellings as required by the “International Fire Code” as adopted and amended by The City of Prescott.
Exception: An automatic sprinkler system shall not be required for additions or alterations to existing buildings that are not already provided with a sprinkler system.
SECTION R309.2.1 Design and Installation is hereby amended to read as follows:
R309.2.1 Design and installation. Automatic sprinkler systems shall be designed and installed in accordance with as required by the “International Fire Code” as adopted and amended by The City of Prescott.
CHAPTER 5 - FLOORS
SECTION R506 CONCRETE FLOORS
SECTION R506.3.3 VAPOR RETARDER is hereby amended to read as follows:
R506.3.3 VAPOR RETARDER. A vapor retarder shall be installed as recommended and specified by the certified geotechnical engineer and must be identified in the geotechnical soils report required by Section R401.4 of this code.
CHAPTER 7 - WALL COVERING
SECTION R702.7 VAPOR RETARDERS to be deleted in its entirety including all table references.
CHAPTER 11 - ENERGY EFFICIENCY
CHAPTER 11 ENERGY EFFICIENCY to be deleted in its entirety to be replaced with the requirements of the "2012 International Energy Conservation Code" as adopted by the City of Prescott and as may be amended from time to time.
CHAPTER 24 - FUEL GAS
SECTION G2408 (305) – INSTALLATION
SECTION G2408.7 – FUTURE GAS STUB is hereby added as a new section as follows:
SECTION G2408.7 - FUTURE GAS STUBS The gas stub-out for a future appliance shall be provided with a shut-off valve equipped with a sealed cap and an approved permanently engraved label shall be affixed to the gas stub-out/shut-off valve that states the maximum allowable BTHU rating of appliance connected to it. Where a gas stub is located above a combustible deck or under a combustible ceiling/roof future appliances must meet the manufacturers specifications and installation instructions regarding proximity to combustible construction.
SECTION G2415 (404): PIPING SYSTEM INSTALLATION
SECTION G2415.13 (404.13): TRENCHES is hereby deleted and replaced as follows:
G2415 (404.13): Trenches - Where trenches are excavated such that the bottom of the trench forms the bed for the pipe, solid and continuous load-bearing support shall be provided between joints. Trench bottoms shall be smooth, flat, and without surface irregularities, otherwise the trench shall be over-excavated, and backfilled to the proper grade with compacted earth, sand, fine gravel or similar granular material. Piping shall not be supported on rocks or blocks at any point. Rocky or unstable soil shall be over-excavated by two or more pipe diameters and brought to the proper grade with suitable compacted granular material. The Bedding material shall not contain rocks larger than 1-1/2 inches in their greatest dimension and must be clear of any debris or organic material. If ABC is used, screened 1” minus material is required.
SECTION G2420 (409) – GAS SHUTOFF VALVES
SECTION G2420.3 (409.3.2) INDIVIDUAL BUILDINGS is hereby amended as follows:
G2420.3 INDIVIDUAL BUILDINGS. In a common system serving more than one building, shutoff valves shall be installed outdoors at each building. The gas line for shut off must break ground prior to entrance in the building and the shutoff installed as well as the dielectric union to the exterior of the building.
CHAPTER 25 PLUMBING ADMINISTRATION
SECTION P2503 INSPECTION AND TESTS
SECTION P2503.4 BUILDING SEWER TESTING is hereby amended as follows:
SECTION P2503.4 BUILDING SEWER TESTING The building sewer shall be watertight at all points.
A forced sewer test shall consist of pressurizing the piping to a pressure of not less than 5 psi (34.5 kPa) greater than the pump rating and maintaining such pressure for not less than 15 minutes. The forced sewer shall be watertight at all points.
CHAPTER 26 – GENERAL PLUMBING REQUIREMENTS
SECTION P2602 – INDIVIDUAL WATER SUPPLY AND SEWAGE DISPOSAL
SECTON P2602.1 GENERAL is hereby amended as follows:
P2602.1 GENERAL The water distribution system of any building or premises where plumbing fixtures are installed shall be connected to a public water supply. Where a public water supply system is not available, or connection to the supply is not feasible, an individual water supply shall be provided. Individual water supplies shall be constructed and installed in accordance with applicable state and local laws, where such laws do not address the requirements set forth in NGWA-01, individual water supplies shall comply with NGWA-01 for those requirements not addressed by state and local laws. Backflow devices are required per Prescott City Code 6-1, Section 903.3.5.
Sanitary drainage piping from plumbing fixtures in buildings and sanitary drainage piping systems from premises shall be connected to a public sewer. Where a public sewer is not available, the sanitary drainage piping and systems shall be connected to a private sewage disposal system approved for use by Yavapai County under separate permit.
SECTION P2603 – STRUCTURAL AND PIPING PROTECTION
SECTION P2603.5.1 SEWER DEPTH is hereby amended to read as follows:
P2603.5.1 SEWER DEPTH. Building sewers that connect to private sewage disposal systems shall be a minimum of 18 inches below finished grade at the point of septic tank connection. Building sewers shall be a minimum of 18 inches below grade.
SECTION P2603.5.2 WATER IN ATTICS is hereby added as follows:
SECTION P2603.5.2 WATER IN ATTICS. All water in attics must be either in a conditioned attic space, or must be in an approved chase with foam, on the conditioned side of the insulation, with a minimum of R-49 insulation over the chase. Pipe must be pex or equal and must slope to drain to showerhead when not in use; no valve allowed on the showerhead.
SECTION P2604 – TRENCHING AND BACKFILLING
SECTION P2604.1: Trenching and Bedding is hereby amended to read as follows:
P2604.1 Trenching and Backfilling - Where trenches are excavated such that the bottom of the trench forms the bed for the pipe, solid and continuous load-bearing support shall be provided between joints. Trench bottoms shall be smooth, flat, and without surface irregularities, otherwise the trench shall be over-excavated, and backfilled to the proper grade with compacted earth, sand, fine gravel or similar granular material. Piping shall not be supported on rocks or blocks at any point. Rocky or unstable soil shall be over-excavated by two or more pipe diameters and brought to the proper grade with suitable compacted granular material. The Bedding material shall not contain rocks larger than 1-1/2 inches in their greatest dimension and must be clear of any debris or organic material. If ABC is used, screened 1” minus material is required.
CHAPTER 27 PLUMBING FIXTURES
SECTION P2709 SHOWER RECEPTORS
SECTION P2709.3 INSTALLATION is hereby amended to read as follows:
SECTION P2709.3 INSTALLATION. Lining materials shall be sloped 1/4 unit vertical in 12 units horizontal (2-percent slope) to weep holes in the subdrain by means of a smooth, solidly formed subbase, shall be properly recessed and fastened to approved backing so as not to occupy the space required for the wall covering, and shall not be nailed or perforated at any point less than 1 inch (25.4 mm) above the finished threshold.
CHAPTER 30: SANITARY DRAINAGE
SECTION P3008 – BACKWATER VALVES
SECTION P3008.1 Where Required is hereby amended to read as follows:
P3008.1 Where required. All structures connected to the City of Prescott sewer system require an approved backwater valve. All structures connected to the City of Prescott sewer system prior to the adoption of this ordinance shall be protected by an approved backwater valve when additions, alterations, or repairs to existing structures are permitted.
CHAPTER 39 POWER AND LIGHTING DISTRIBUTION
SECTION E3901 RECEPTACLE OUTLETS
SECTION E3901.4.2 ISLAND AND PENINSULAR COUNTERTOPS AND WORK SURFACES is hereby deleted in its entirety.
E3901.4.3 RECEPTACLE OUTLET LOCATION is amended by adding Item 4 as follows:
E3901.4.3 RECEPTACLE OUTLET LOCATION Receptacle outlets rendered not readily accessible by appliances fastened in place, appliance garages, sinks, or range tops as covered in the exception to Section E3901.4.1, or appliances occupying assigned spaces shall not be considered as these required outlets. Required receptacle outlets shall be located in one or more of the following:
1. On or above, but not more than 20 inches (508 mm) above, the countertop or work surface.
2. In a countertop using receptacle outlet assemblies listed for the use in countertops.
3. In a work surface using receptacle outlet assemblies listed for use in work surfaces or listed for use in countertops. [210.52(C)(3)]
4. Receptacles are allowed below the countertop at a maximum of 12” below the top of the countertop surface measured to the middle of the box, when the countertop surface overhang does not exceed 1.5 inches
(Ord. 2025-1924, 11-18-2025)
3-8-3 PENALTY:
(A) PENALTY – CRIMINAL: Any person who violates any provision of this chapter or the codes adopted pursuant to this chapter may be guilty of a misdemeanor and, upon conviction thereof, shall be punished as provided in Section 1-3-1, by a fine not exceeding two thousand five hundred dollars ($2,500.00) or by imprisonment for not more than six (6) months, or by both such fine and imprisonment, at the discretion of the City judge. Each and every day any such violation continues shall be deemed and considered a separate offense.
(B) PENALTY – CIVIL: Upon conviction any person who violates any provision of this chapter thereof may be punished as provided in Sections 1-3-1 and 1-3-2 and subject to a civil penalty. Each and every day any such violation continues shall be deemed and considered a separate offense. (Ord. 4161, 10-30-2001, eff. 1-1-2002; amd. Ord. 4389, 4-13-2004; amd. Ord. 4603, 09-11-2007, eff. 10-15-2007; amd. Ord. 4677-0920 12-09-2008, eff. 01-08-2009; Ord. 4902-1440, 9-23-2014; Ord. 4930-1468, 4-14-2015; Ord. 2019-1665, 6-11-2019; Ord. 2025-1924, 11-18-2025)