Virginia Climate Zones by County
Virginia's 136 counties span climate zones 3A to 5A under the 2021 International Energy Conservation Code (IECC). Zone 4A is the most common, with 111 of the 136. For reference, Virginia Beach is in zone 3A and Richmond and Roanoke are in 4A.
Insulation minimums for each zone in Virginia
| Zone | Counties | Attic | Wood-frame walls | Floors over unheated space | Basement walls |
|---|---|---|---|---|---|
| 3A | 20 | R-49 | R-20, or 13+5ci, or R-15ci | R-19 | R-5ci or R-13 |
| 4A | 111 | R-60 | R-30, or 20+5ci, or 13+10ci, or R-20ci | R-19 | R-10ci or R-13 |
| 5A | 5 | R-60 | R-30, or 20+5ci, or 13+10ci, or R-20ci | R-30 | R-15ci, or R-19, or 13+5ci |
Minimums from the 2021 IECC (Table R402.1.3). Many areas still enforce an older edition, so check with your local building department. See sources.
Which energy code Virginia uses
Virginia enforces the 2021 IECC with amendments for homes (in effect since Jan 2024). Source: US Department of Energy, September 2026. Local governments can adopt newer codes or amendments. See every state's energy code.
What changed from the 2018 map
In the 2021 map, 19 moved warmer and five moved colder: Alleghany County (4 → 5), Bath County (4 → 5), Brunswick County (4 → 3), Chesapeake (independent city) (4 → 3), Clifton Forge (independent city) (4 → 5), Covington (independent city) (4 → 5), Emporia (independent city) (4 → 3), Franklin County (4 → 3), Franklin (independent city) (4 → 3), Greensville County (4 → 3), Halifax County (4 → 3), Hampton (independent city) (4 → 3), and 12 more marked in the table below. If your town still enforces the 2018 or 2015 code, the older zone applies to permits.
Every county in Virginia
| Name | Zone (2021) | Zone (2018) | Details |
|---|---|---|---|
| Accomack County | 4A | 4A | Insulation → |
| Albemarle County | 4A | 4A | Insulation → |
| Alexandria (independent city) | 4A | 4A | Insulation → |
| Alleghany County | 5A | 4A changed | Insulation → |
| Amelia County | 4A | 4A | Insulation → |
| Amherst County | 4A | 4A | Insulation → |
| Appomattox County | 4A | 4A | Insulation → |
| Arlington County | 4A | 4A | Insulation → |
| Augusta County | 4A | 4A | Insulation → |
| Bath County | 5A | 4A changed | Insulation → |
| Bedford County | 4A | 4A | Insulation → |
| Bedford (independent city) | 4A | 4A | Insulation → |
| Bland County | 4A | 4A | Insulation → |
| Botetourt County | 4A | 4A | Insulation → |
| Bristol (independent city) | 4A | 4A | Insulation → |
| Brunswick County | 3A | 4A changed | Insulation → |
| Buchanan County | 4A | 4A | Insulation → |
| Buckingham County | 4A | 4A | Insulation → |
| Buena Vista (independent city) | 4A | 4A | Insulation → |
| Campbell County | 4A | 4A | Insulation → |
| Caroline County | 4A | 4A | Insulation → |
| Carroll County | 4A | 4A | Insulation → |
| Charles City County | 4A | 4A | Insulation → |
| Charlotte County | 4A | 4A | Insulation → |
| Charlottesville (independent city) | 4A | 4A | Insulation → |
| Chesapeake (independent city) | 3A | 4A changed | Insulation → |
| Chesterfield County | 4A | 4A | Insulation → |
| Clarke County | 4A | 4A | Insulation → |
| Clifton Forge (independent city) | 5A | 4A changed | Insulation → |
| Colonial Heights (independent city) | 4A | 4A | Insulation → |
| Covington (independent city) | 5A | 4A changed | Insulation → |
| Craig County | 4A | 4A | Insulation → |
| Culpeper County | 4A | 4A | Insulation → |
| Cumberland County | 4A | 4A | Insulation → |
| Danville (independent city) | 4A | 4A | Insulation → |
| Dickenson County | 4A | 4A | Insulation → |
| Dinwiddie County | 4A | 4A | Insulation → |
| Emporia (independent city) | 3A | 4A changed | Insulation → |
| Essex County | 4A | 4A | Insulation → |
| Fairfax County | 4A | 4A | Insulation → |
| Fairfax (independent city) | 4A | 4A | Insulation → |
| Falls Church (independent city) | 4A | 4A | Insulation → |
| Fauquier County | 4A | 4A | Insulation → |
| Floyd County | 4A | 4A | Insulation → |
| Fluvanna County | 4A | 4A | Insulation → |
| Franklin County | 3A | 4A changed | Insulation → |
| Franklin (independent city) | 3A | 4A changed | Insulation → |
| Frederick County | 4A | 4A | Insulation → |
| Fredericksburg (independent city) | 4A | 4A | Insulation → |
| Galax (independent city) | 4A | 4A | Insulation → |
| Giles County | 4A | 4A | Insulation → |
| Gloucester County | 4A | 4A | Insulation → |
| Goochland County | 4A | 4A | Insulation → |
| Grayson County | 4A | 4A | Insulation → |
| Greene County | 4A | 4A | Insulation → |
| Greensville County | 3A | 4A changed | Insulation → |
| Halifax County | 3A | 4A changed | Insulation → |
| Hampton (independent city) | 3A | 4A changed | Insulation → |
| Hanover County | 4A | 4A | Insulation → |
| Harrisonburg (independent city) | 4A | 4A | Insulation → |
| Henrico County | 4A | 4A | Insulation → |
| Henry County | 4A | 4A | Insulation → |
| Highland County | 5A | 4A changed | Insulation → |
| Hopewell (independent city) | 4A | 4A | Insulation → |
| Isle of Wight County | 3A | 4A changed | Insulation → |
| James City County | 4A | 4A | Insulation → |
| King and Queen County | 4A | 4A | Insulation → |
| King George County | 4A | 4A | Insulation → |
| King William County | 4A | 4A | Insulation → |
| Lancaster County | 4A | 4A | Insulation → |
| Lee County | 4A | 4A | Insulation → |
| Lexington (independent city) | 4A | 4A | Insulation → |
| Loudoun County | 4A | 4A | Insulation → |
| Louisa County | 4A | 4A | Insulation → |
| Lunenburg County | 4A | 4A | Insulation → |
| Lynchburg (independent city) | 4A | 4A | Insulation → |
| Madison County | 4A | 4A | Insulation → |
| Manassas (independent city) | 4A | 4A | Insulation → |
| Manassas Park (independent city) | 4A | 4A | Insulation → |
| Martinsville (independent city) | 4A | 4A | Insulation → |
| Mathews County | 4A | 4A | Insulation → |
| Mecklenburg County | 3A | 4A changed | Insulation → |
| Middlesex County | 4A | 4A | Insulation → |
| Montgomery County | 4A | 4A | Insulation → |
| Nelson County | 4A | 4A | Insulation → |
| New Kent County | 4A | 4A | Insulation → |
| Newport News (independent city) | 3A | 4A changed | Insulation → |
| Norfolk (independent city) | 3A | 4A changed | Insulation → |
| Northampton County | 4A | 4A | Insulation → |
| Northumberland County | 4A | 4A | Insulation → |
| Norton (independent city) | 4A | 4A | Insulation → |
| Nottoway County | 4A | 4A | Insulation → |
| Orange County | 4A | 4A | Insulation → |
| Page County | 4A | 4A | Insulation → |
| Patrick County | 4A | 4A | Insulation → |
| Petersburg (independent city) | 4A | 4A | Insulation → |
| Pittsylvania County | 3A | 4A changed | Insulation → |
| Poquoson (independent city) | 4A | 4A | Insulation → |
| Portsmouth (independent city) | 3A | 4A changed | Insulation → |
| Powhatan County | 4A | 4A | Insulation → |
| Prince Edward County | 4A | 4A | Insulation → |
| Prince George County | 4A | 4A | Insulation → |
| Prince William County | 4A | 4A | Insulation → |
| Pulaski County | 4A | 4A | Insulation → |
| Radford (independent city) | 4A | 4A | Insulation → |
| Rappahannock County | 4A | 4A | Insulation → |
| Richmond County | 4A | 4A | Insulation → |
| Richmond (independent city) | 4A | 4A | Insulation → |
| Roanoke County | 4A | 4A | Insulation → |
| Roanoke (independent city) | 4A | 4A | Insulation → |
| Rockbridge County | 4A | 4A | Insulation → |
| Rockingham County | 4A | 4A | Insulation → |
| Russell County | 4A | 4A | Insulation → |
| Salem (independent city) | 4A | 4A | Insulation → |
| Scott County | 4A | 4A | Insulation → |
| Shenandoah County | 4A | 4A | Insulation → |
| Smyth County | 4A | 4A | Insulation → |
| South Boston County | 3A | 3A | Insulation → |
| Southampton County | 3A | 4A changed | Insulation → |
| Spotsylvania County | 4A | 4A | Insulation → |
| Stafford County | 4A | 4A | Insulation → |
| Staunton (independent city) | 4A | 4A | Insulation → |
| Suffolk (independent city) | 3A | 4A changed | Insulation → |
| Surry County | 3A | 4A changed | Insulation → |
| Sussex County | 3A | 4A changed | Insulation → |
| Tazewell County | 4A | 4A | Insulation → |
| Virginia Beach (independent city) | 3A | 4A changed | Insulation → |
| Warren County | 4A | 4A | Insulation → |
| Washington County | 4A | 4A | Insulation → |
| Waynesboro (independent city) | 4A | 4A | Insulation → |
| Westmoreland County | 4A | 4A | Insulation → |
| Williamsburg (independent city) | 4A | 4A | Insulation → |
| Winchester (independent city) | 4A | 4A | Insulation → |
| Wise County | 4A | 4A | Insulation → |
| Wythe County | 4A | 4A | Insulation → |
| York County | 4A | 4A | Insulation → |
Source: Pacific Northwest National Laboratory, Guide to Determining Climate Zone by County: Building America and IECC 2021 Updates (2022).
Frequently asked questions
What climate zone is Virginia?
Virginia spans IECC climate zones 3A to 5A; zone 4A is the most common. Find your county in the table above, or search by ZIP code.
How much attic insulation do I need in Virginia?
In Virginia, the 2021 IECC calls for R-49 and R-60 in the attic, depending on the zone. The table near the top of this page lists each zone's minimums.
What energy code does Virginia use?
Virginia enforces the 2021 IECC with amendments for homes (in effect since Jan 2024). Source: US Department of Energy, September 2026. Local governments can adopt newer codes or amendments.
More for Virginia: Last frost dates in Virginia · Virginia planting zones · Frost line depth by state