Climate Zone 5 — Cool
Zone 5 covers a broad swath of the northern United States and includes major population centers like Chicago, Boston, Denver, and Pittsburgh. Heating is the dominant energy concern, with cold winters that can produce extended periods of sub-freezing temperatures. The DOE recommendations for this zone are identical to Zone 4 in most categories, but the increased heating degree days mean that the economic payback period for insulation upgrades is shorter. Proper air sealing is critical in Zone 5 to prevent warm, moist interior air from reaching cold surfaces within the building envelope where it can condense.
Zone 5 Climate Data
R-Value Requirements for Zone 5
The table below lists the DOE recommended insulation R-values for every building component in Climate Zone 5 (Cool). 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-49 | View insulation options → |
| Wall Cavity | R-13 | View insulation options → |
| Wall Continuous | R-5 | View insulation options → |
| Floor | R-25 | View insulation options → |
| Basement Wall | R-10 | View insulation options → |
| Crawlspace | R-10 | View insulation options → |
| Cathedral Ceiling | R-38 | View insulation options → |
| Garage Ceiling | R-30 | View insulation options → |
Insulation Thickness by Type for Zone 5 Attic (R-49)
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-49 recommendation for Zone 5 attics, along with the estimated material cost per square foot.
| Insulation Type | R/Inch | Thickness Needed | Cost/SqFt | DIY? |
|---|---|---|---|---|
| Fiberglass Batt | R-3.2 | 15.3" | $5.88 | Yes |
| Blown-In Fiberglass | R-2.5 | 19.6" | $3.92 | Pro |
| Blown-In Cellulose | R-3.5 | 14" | $3.43 | Yes |
| Open-Cell Spray Foam | R-3.7 | 13.2" | $19.60 | Pro |
| Closed-Cell Spray Foam | R-6.5 | 7.5" | $39.20 | Pro |
| Mineral Wool Batt | R-3.3 | 14.8" | $7.35 | Yes |
| Mineral Wool Board | R-4.3 | 11.4" | $12.25 | Yes |
| Extruded Polystyrene (XPS) | R-5 | 9.8" | $8.82 | Yes |
| Expanded Polystyrene (EPS) | R-3.9 | 12.6" | $5.88 | Yes |
| Polyisocyanurate (Polyiso) | R-6 | 8.2" | $10.78 | Yes |
| Cotton Denim (Recycled) | R-3.5 | 14" | $9.80 | Yes |
| Sheep Wool | R-3.5 | 14" | $17.15 | Yes |
| Aerogel Blanket | R-10 | 4.9" | $147.00 | Yes |
| Vermiculite (Loose Fill) | R-2.1 | 23.3" | $4.90 | Yes |
Insulation Strategy for Zone 5
Zone 5 insulation requirements match Zone 4 in most categories, but the higher heating degree days mean that every gap in the thermal envelope has a greater impact on energy costs. The R-49 attic requirement and R-13 plus R-5 wall system are identical to Zone 4. However, the economic payback for insulation upgrades is significantly shorter in Zone 5 due to the longer heating season and higher energy bills. Advanced framing techniques such as 2x6 studs at 24 inches on center provide deeper cavities for R-20 batt insulation while reducing the amount of lumber (and thermal bridging) in the wall assembly. Attention to air sealing is particularly important because the stack effect in winter creates strong pressure differences that drive warm air out through upper-level penetrations.
States in Climate Zone 5
The following states include areas that fall within DOE Climate Zone 5. 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.