Sub-sections in this division:
Climatic Design Criteria — Wind & Seismic
Wind speed 98 mph for elevations below 3,900 ft; Seismic Design Category D; frost line 1 ft below 5,000 ft; termite risk Moderate to Heavy. Wind exposure category C unless site-specific justification provided. Above 3,900 ft: defer to IBC.
IRC Table R301.2 (locally amended)
Energy Efficiency — Insulation Minimums (Climate Zone 3)
Ceiling: R-38. Wood-framed wall: R-20 or R-13+5ci or 0+15ci. Floor: R-19 or R-13+5ci or 15ci. Unheated slab edge: none required. Vertical fenestration: max U-factor 0.30, max SHGC 0.25. Skylight: max U-factor 0.53, max SHGC 0.28.
IECC 2024 Tables R402.1.2 and R402.1.3 (Climate Zone 3)
Foundation Drainage — Grade Slope Requirements
Grade must slope away at minimum 5% for 10 ft from foundation. Impervious surfaces within 10 ft: minimum 2% slope away. Swales within 10 ft: minimum 1% along flow line. Exception: low expansive/collapsible/soluble soils permit 2% slope.
IRC R401.3 (locally amended)
Foundation Waterproofing — When Required
Required only where geotechnical report indicates high water table or severe soil-water conditions. Where required: from finished grade to top of footing or 6 in below basement floor. Options include two-ply hot-mopped felts, 55 lb roll roofing, 40-mil polymer-modified asphalt, 60-mil flexible polymer cement, 1/8 in cement-based fiber-reinforced coating, or 60-mil solvent-free liquid-applied synthetic rubber.
IRC R406.2 (locally amended)
Masonry Fences and Retaining Walls — Permit Required
Separate building permit required per parcel for fences, walls, and retaining walls. Retaining walls retaining more than 24 inches require engineering by a registered design professional. Footings must be designed by a registered Civil or Structural Engineer for all imposed loads including soil pressure, surcharge, seismic, and hydrostatic forces per IBC Chapter 18. Default design parameters where no soils report: assume 60 psf/ft lateral soil pressure, Exposure Class S2 (severe sulfate exposure) — concrete minimum f'c 4,000 psi for footings in sulfate soils. No fence or wall may block a natural flow path. Prohibited materials: pointed pickets, electrocution components, embedded glass, barbed/razor wire.
IBC 2024 Appendix Q / Henderson Development Code Section 19.10.6
Retaining Wall — Footing and Structural Design Requirements
Retaining walls over 24 inches (top of footing to top of wall) require a building permit and engineering by a registered Civil or Structural Engineer. Footing design must account for: lateral soil pressure (minimum 60 psf/ft unless geotechnical report specifies otherwise), surcharge loads, seismic forces (Seismic Design Category D), and hydrostatic pressure where applicable. Concrete minimum compressive strength f'c = 3,000 psi general; f'c = 4,000 psi where soils report indicates Exposure Class S2 (severe sulfate) conditions, which is common in Southern Nevada soils. Footings must extend below frost depth (minimum 12 inches below finish grade in the Las Vegas Valley). Required inspections: footing excavation, reinforcing steel placement, drainage/dampproofing before backfill.
IBC 2024 Appendix Q / IBC Chapter 18 / Henderson Municipal Code Section 15.08
Townhouse — Structural Independence
Each townhouse unit must be structurally independent except: shared foundations, structural sheathing fastened to common wall framing, nonstructural coverings, flashing at common wall roof termination, and units separated by common wall per R302.2.2.
IRC R302.2.6 (locally amended)
Vapor Retarder Under Slab
Minimum 10-mil polyethylene meeting ASTM E1745 Class A; joints lapped not less than 6 inches. Exceptions: garages, unheated storage under 70 sq ft, driveways/walks/patios.
IRC R506.3.3 (locally amended)
Weep Screed — Stucco Base
Minimum 26-gauge galvanized corrosion-resistant weep screed with 3.5 in vertical attachment flange. Placed at or below foundation plate line; minimum 4 in above grade and 2 in above paved areas. Pool note: maintain minimum 2 in clearance between cool deck/patio and stucco weep screed.
IRC R703.7.2.1 / IBC Section 2512.1.2
Climatic & Geographic Design Criteria
Las Vegas design values (below 1,600 ft elevation): Ground snow load 5 psf; Design wind speed 98 mph; Seismic Design Category D; Frost line depth 1 ft; Termite: Moderate to Heavy. These SNBO-published values replace the generic IRC table and govern all structural design.
SNBO 2024 IRC Amendment, Table R301.2
Flatwork & Pavement Standards
Off-site concrete: Type V cement required, minimum 3,000 PSI @ 28 days, mix designs approved by City prior to use. AC pavement must be 1/2 inch above lip of all gutters after compaction. Asphalt mix design must be submitted and approved by City Engineer prior to placement in City ROW.
CLV General Notes §5, §8, §17 (Jan 2026)
Foundation Drainage
Section R401.3 is locally amended for desert conditions. Drainage must slope away from foundations. The SNBO amendment modifies the base IRC requirement to address local soil and drainage conditions.
SNBO 2024 IRC Amendment §R401.3
Foundation Requirements & Soils Report
Plans must show all footings, posts, bearing walls, slabs, stem walls, anchor bolts, hold-downs, reinforcement size/depth, and material specs. A soils report is required for all new structures with a footprint of 600 sq ft or greater.
CLV Residential Submittal Requirements §1.3.B; IRC R401.4
Foundation Waterproofing & Dampproofing
Section R406.2 (foundation waterproofing and dampproofing) is specifically amended for Southern Nevada conditions. When basements are installed, plans must show a cross-section with materials, exterior waterproofing, and egress window well details.
SNBO 2024 IRC Amendment §R406.2; IRC R406
Gas Piping Under Slabs
Gas piping installed underground beneath buildings is extensively amended. All gas lines under slabs and foundations must be sleeved per UPC §1210.1.6. Three standard details govern installation: P-102, P-103, and P-104. LP gas procedures follow P-101.
SNBO 2024 UPC §1210.1.6 as amended; CLV Standard Details P-101 through P-104
Special Inspections (QAA Program)
Special inspections are required per the CLV Quality Assurance and Approval (QAA) procedures. QAA1 through QAA9 procedures govern reporting, non-compliance, revisions, final reports, structural observation, and epoxy anchor inspections.
CLV QAA Special Inspection Program; IBC Chapter 17