Nevada REScheck Requirements (2026)

Key facts:

• 2024 IECC — GOE Adopted August 18, 2024

• Climate Zones 3B (Las Vegas) & 5B (Reno)

• Local Enforcement Dates Vary

• Blower Door: 3 ACH50 Mandatory

 

Nevada commonly requires REScheck for: new residential construction, additions and alterations, conditioned detached structures, barndominiums and ADUs. Nevada has a two-tier structure — the Governor's Office of Energy adopts the IECC statewide and local jurisdictions enforce on their own schedules. Clark County (Las Vegas) and Washoe County (Reno) are the two dominant markets, each on the 2024 IECC. Always verify the currently enforced code edition with the local permit office.

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Nevada jurisdictions require REScheck and energy compliance documentation under NRS 701.220. The Nevada Governor's Office of Energy (GOE) adopted the 2024 IECC effective August 18, 2024. Local municipalities enforce on their own schedules: Clark County began enforcing January 11, 2026; Washoe County began July 1, 2025.

 

⚠ Nevada's Local Enforcement Dates Vary — Always Verify with Your Jurisdiction: Clark County (Las Vegas metro) began enforcing January 11, 2026. The City of Las Vegas began January 5, 2026. Washoe County (Reno) began July 1, 2025. Many rural Nevada counties are still transitioning. A project in Elko County or Nye County may still be on an earlier edition while Las Vegas is on the 2024 IECC — confirm before submitting a permit.

 

Nevada's Two-Tier Adoption Structure

NRS 701.220 requires the GOE to adopt the most recently published IECC on a triennial basis. Local governments must follow and may adopt more stringent amendments, but cannot adopt less stringent codes.

• 2024 IECC — adopted by Nevada GOE effective August 18, 2024

• Clark County / Las Vegas: enforcement began January 2026

• Washoe County / Reno: enforcement began July 1, 2025

• Rural Nevada counties: transitioning — verify with local permit office

• No local jurisdiction may adopt a weaker energy code than the GOE standard

• ASHRAE 90.1-2022 also accepted as a commercial compliance path

 

Common Permit Requirements

• REScheck compliance report (prescriptive or UA trade-off path)

• Manual J HVAC load calculations

• Window and door schedule (U-factor and SHGC per NFRC)

• Blower door test results — 3 ACH50 maximum (mandatory under 2024 IECC)

• Duct leakage test results

• Air barrier inspection checklist (Table R402.4.2)

• Energy certificate posted at electrical panel

• Clark County: verify current local energy code amendments at time of permit

 

Nevada's Compliance Pathways (2024 IECC)

Pathway  ·  How It Works

• Prescriptive (Table R402.1.2):  Zone 3B: ceiling R-38, walls R-20/R-13+5ci, floor R-13, window U-0.32, SHGC 0.25. Zone 5B: ceiling R-49, walls R-20+5ci or R-13+10ci, floor R-30, basement R-15/19, window U-0.30. No REScheck required.

• UA Trade-Off / REScheck:  Total UA ≤ reference design UA (§R402.1.5). SHGC 0.25 in Zone 3B is still mandatory, can't be traded off.

• Performance / ERI:  Total Building Performance (R405): energy cost ≤ 95% reference design. ERI/HERS path under R406. HERS Rater required.

 

Nevada Climate Zones

Zone  ·  Coverage  ·  Classification  ·  Primary Design Challenge

• 3B:  Clark County only — Las Vegas, Henderson, North Las Vegas, Boulder City, Mesquite, Laughlin, Pahrump (Nye County below 4,000 ft)   —   Hot-Dry   —   Extreme cooling loads; SHGC 0.25 mandatory; summer temps 110°F+

• 5B:  All other 16 counties — Washoe (Reno), Carson City, Douglas, Lyon, Storey, Churchill, Mineral, Esmeralda, Nye (above 4,000 ft), Elko, Eureka, Lander, Humboldt, Pershing, Lincoln, White Pine; also Clark Co. above 4,000 ft   —   Cold-Dry   —   Cold winters; R-49 ceilings; continuous wall insulation; no SHGC restriction; Reno design temp -2°F

 

⚠ Nye County Altitude Exception: Nye County straddles both zones. Below 4,000 ft (including Pahrump, the county's largest city) is Zone 3B. Above 4,000 ft (including Tonopah) is Zone 5B. Always confirm elevation and zone with the local building department.

 

Zone 3B vs. Zone 5B Insulation Comparison (2024 IECC)

Requirement  ·  Zone 3B (Las Vegas)  ·  Zone 5B (Reno)

• Ceilings:  R-38 min   —   R-49 min

• Wood Frame Walls:  R-20 cavity-only OR R-13+5ci   —   R-20+5ci or R-13+10ci (cavity-only not allowed)

• Floor:  R-13 min   —   R-30 min

• Basement Walls:  R-5ci or R-13 cavity (rare; mostly slab-on-grade)   —   R-15ci or R-19 cavity

• Slab Edge:  Not typically required   —   R-10 at 2 ft

• Windows:  U-0.32 max   —   U-0.30 max

• SHGC:  0.25 max — strictly enforced   —   No restriction

 

The Two-Nevada Reality: Las Vegas (Zone 3B) has lower insulation requirements but a critical SHGC 0.25 ceiling. Reno (Zone 5B) has much stricter insulation — R-49 ceilings, continuous wall insulation, R-30 floors. A builder moving between the two must completely reset their specifications.

 

Blower Door and Duct Requirements

Air Leakage — 2024 IECC

• Mandatory: 3 ACH50 maximum for both Zone 3B and Zone 5B

• Testing required after rough-in and after all envelope penetrations are installed

• Testing per RESNET/ICC 380, ASTM E779, or ASTM E1827

• Prior 2018 IECC (Las Vegas amendments) allowed 4 ACH50 for Zone 3B — the 2024 IECC tightens this to 3 ACH50 statewide

• Visual inspection may remain an alternative under some still-active older editions — verify which edition applies

 

Duct Leakage Requirements

• Total duct leakage: max 4 CFM25 per 100 sq ft — mandatory under 2024 IECC

• In Las Vegas, attic duct systems (150°F+) are the dominant leakage failure point

• R-8 minimum insulation for supply ducts in unconditioned attics

• Rough-in duct testing (without air handler): max 4 CFM25/100 sq ft

• Framing cavities may NOT be used as ducts

 

Is REScheck Required in Nevada?

• New single-family homes

• Duplexes and townhomes

• Conditioned residential additions and alterations

• Finished basement conversions

• Garage conversions to conditioned space

• Conditioned barndominiums

• Accessory dwelling units (ADUs) — a major Clark County market

• Conditioned detached structures

 

Nevada-Specific Notes

• No local jurisdiction may adopt a weaker code than the 2024 IECC GOE standard

• Locals may amend it stricter — verify current local amendments in Clark County, City of Las Vegas, Washoe County

• Zone 3B's 0.25 SHGC maximum is one of the strictest in the nation

• Nevada's ADU legislation has significantly increased ADU permit volume statewide — all conditioned ADUs must comply

• REScheck accepted as UA trade-off documentation in both Clark and Washoe Counties

 

Common REScheck Failure Reasons in Nevada

Zone 3B (Las Vegas) Common Errors

• SHGC failure — 0.25 max is extremely strict; standard clear double-pane windows don't meet it; can't be traded off

• Wrong code year — Clark County went to 2024 IECC January 11, 2026; verify which edition applies near the transition date

• Incorrect altitude zone assignment — areas above 4,000 ft (Mount Charleston, Blue Diamond) are Zone 5B, not 3B

• Duct insulation below R-8 in attic — Las Vegas attic temps require full R-8

• Missing duct leakage documentation

 

Zone 5B (Reno/Northern Nevada) Common Errors

• Using Zone 3B values for Zone 5B projects — R-38 ceiling/R-20 walls instead of required R-49 and continuous insulation

• Missing continuous wall insulation — cavity-only R-20 not allowed on the prescriptive path in Zone 5B

• Wrong code year for Washoe County (went to 2024 IECC July 1, 2025)

• Missing basement insulation documentation (R-15/19 required)

• Blower door failures — 3 ACH50 is strict; rim joists, top plates, window rough openings are common failure points

• Slab-edge insulation omitted (R-10 at 2 ft required)

 

Major Cities and Jurisdictions

Las Vegas, Henderson & Clark County (Zone 3B)

Nevada's dominant residential market — about 75% of the state's population. 2024 IECC took effect for Clark County January 11, 2026, City of Las Vegas January 5, 2026. Key requirements: SHGC 0.25, R-38 ceilings, 3 ACH50 blower door, R-8 attic duct insulation.

 

Pahrump (Nye County below 4,000 ft — Zone 3B)

Nevada's largest unincorporated community, ~2,700 ft elevation — Zone 3B despite being ~60 miles from Las Vegas. Confirm elevation for the zone exception.

 

Reno, Sparks & Washoe County (Zone 5B)

Nevada's second-largest market, driven by California in-migration and logistics growth. Washoe County adopted 2024 IECC effective July 1, 2025 with a transition through January 1, 2026.

 

Carson City & Douglas County (Zone 5B)

Includes Lake Tahoe-area construction (Minden, Gardnerville, Stateline) with high-altitude conditions more demanding than code minimum in places.

 

Elko, Ely & Rural Northern Nevada (Zone 5B)

Cold-climate counties; Elko's winter design temp of approximately -11°F is among the coldest in the state. Rural offices vary in enforcement capacity.

 

Frequently Asked Questions

What energy code does Nevada currently use?

The GOE adopted the 2024 IECC effective August 18, 2024 (NRS 701.220). Local enforcement varies: Clark County began January 11, 2026; City of Las Vegas January 5, 2026; Washoe County July 1, 2025. Rural counties may still be transitioning — confirm with the local jurisdiction.

 

What climate zones does Nevada have?

Zone 3B (Hot-Dry) covers Clark County and Nye County below 4,000 ft. Zone 5B (Cold-Dry) covers all other 16 counties plus Clark County above 4,000 ft and Nye County above 4,000 ft.

 

Is blower door testing required in Nevada?

Yes, under the 2024 IECC now enforced in Clark and Washoe Counties: mandatory 3 ACH50 max for both zones — stricter than the prior 2018 IECC's 4 ACH50 for Zone 3B. Some rural jurisdictions on older editions may still allow visual inspection.

 

What is the SHGC requirement in Las Vegas (Zone 3B)?

0.25 maximum under the 2024 IECC — one of the strictest in the country. Standard double-pane windows without specialized low-e coatings typically can't meet it. Mandatory, can't be traded off.

 

What are the insulation requirements for Reno (Zone 5B)?

Ceiling R-49, walls R-20+5ci or R-13+10ci (continuous insulation mandatory), floor R-30, basement R-15ci or R-19 cavity, slab R-10 at 2 ft, windows U-0.30 max. No SHGC maximum in Zone 5B.

 

Can Nevada municipalities adopt stricter energy codes?

Yes, under NRS 701.220 — they cannot adopt less stringent requirements. Clark County and City of Las Vegas have historically adopted local amendments; always verify current ones at permit time.