Climate Zone 6 — Cold
Zone 6 represents the cold climate regions of the northern United States, including cities like Minneapolis, Milwaukee, Burlington, and Portland Maine. Winters are long and severe with extended sub-zero periods, making heating the overwhelming energy priority. The DOE significantly increases insulation recommendations for this zone, particularly for attics (R-60) and continuous wall insulation (R-10). Buildings in Zone 6 must be designed with careful attention to moisture management, as the large temperature differential between interior and exterior creates strong vapor drives that can lead to condensation within wall and roof assemblies if not properly addressed.
Zone 6 Climate Data
R-Value Requirements for Zone 6
The table below lists the DOE recommended insulation R-values for every building component in Climate Zone 6 (Cold). Click on any component to see detailed insulation type comparisons, thickness requirements, and cost estimates specific to that component in this climate zone.
| Building Component | Required R-Value | Details |
|---|---|---|
| Attic | R-60 | View insulation options → |
| Wall Cavity | R-13 | View insulation options → |
| Wall Continuous | R-10 | View insulation options → |
| Floor | R-25 | View insulation options → |
| Basement Wall | R-15 | View insulation options → |
| Crawlspace | R-10 | View insulation options → |
| Cathedral Ceiling | R-49 | View insulation options → |
| Garage Ceiling | R-38 | View insulation options → |
Insulation Thickness by Type for Zone 6 Attic (R-60)
The attic is typically the most cost-effective location for insulation in any climate zone. The table below shows the thickness of each insulation type needed to achieve the R-60 recommendation for Zone 6 attics, along with the estimated material cost per square foot.
| Insulation Type | R/Inch | Thickness Needed | Cost/SqFt | DIY? |
|---|---|---|---|---|
| Fiberglass Batt | R-3.2 | 18.8" | $7.20 | Yes |
| Blown-In Fiberglass | R-2.5 | 24" | $4.80 | Pro |
| Blown-In Cellulose | R-3.5 | 17.1" | $4.20 | Yes |
| Open-Cell Spray Foam | R-3.7 | 16.2" | $24.00 | Pro |
| Closed-Cell Spray Foam | R-6.5 | 9.2" | $48.00 | Pro |
| Mineral Wool Batt | R-3.3 | 18.2" | $9.00 | Yes |
| Mineral Wool Board | R-4.3 | 14" | $15.00 | Yes |
| Extruded Polystyrene (XPS) | R-5 | 12" | $10.80 | Yes |
| Expanded Polystyrene (EPS) | R-3.9 | 15.4" | $7.20 | Yes |
| Polyisocyanurate (Polyiso) | R-6 | 10" | $13.20 | Yes |
| Cotton Denim (Recycled) | R-3.5 | 17.1" | $12.00 | Yes |
| Sheep Wool | R-3.5 | 17.1" | $21.00 | Yes |
| Aerogel Blanket | R-10 | 6" | $180.00 | Yes |
| Vermiculite (Loose Fill) | R-2.1 | 28.6" | $6.00 | Yes |
Insulation Strategy for Zone 6
Zone 6 represents a significant step up in insulation requirements, with R-60 attic insulation and R-13 plus R-10 continuous wall insulation. Achieving R-60 in the attic requires 17-24 inches of blown insulation depending on the material. The continuous wall insulation requirement of R-10 typically means 2 inches of rigid foam or mineral wool board on the exterior of the wall sheathing. In this zone, moisture management becomes critically important because the large temperature differential between interior and exterior creates strong vapor drives. The continuous exterior insulation helps keep the wall sheathing above the dew point, reducing the risk of condensation within the wall assembly. Double-stud wall assemblies and structural insulated panels are increasingly common in Zone 6 construction as alternatives to exterior continuous insulation.
States in Climate Zone 6
The following states include areas that fall within DOE Climate Zone 6. Note that many states span multiple climate zones, so specific locations within a state may have different insulation requirements. Click any state to see the specific zones that apply and the complete insulation recommendations for each area.
Other Climate Zones
Compare insulation requirements across climate zones to understand how your location's needs compare to other regions. Each zone page includes complete R-value tables, state listings, and insulation strategies.