Insulation, Roofing & Exterior
R-values by climate zone, insulation types compared, roofing materials, windows, and exterior maintenance.
Insulation R-Values by Climate Zone
| Component | Zone 1-2 | Zone 3 | Zone 4-5 | Zone 6-8 |
|---|
| Attic | R-30 | R-38 | R-49 | R-60 |
| Cathedral Ceiling | R-22 | R-30 | R-38 | R-49 |
| Walls (2x4) | R-13 | R-13 | R-13+5ci | R-13+10ci |
| Walls (2x6) | R-13 | R-20 | R-20 | R-20+5ci |
| Floor over unconditioned | R-13 | R-19 | R-30 | R-38 |
| Basement Walls | R-0 | R-5ci | R-10ci | R-15ci |
Insulation Types
| Type | R/Inch | Cost/sqft | Best For |
|---|
| Fiberglass Batts | R-3.0-3.7 | $0.50-$1.00 | Walls, attic |
| Cellulose (Blown) | R-3.2-3.8 | $0.60-$1.20 | Attic, existing walls |
| Open-Cell Spray Foam | R-3.5-3.7 | $1.00-$2.00 | Walls, roof deck |
| Closed-Cell Spray Foam | R-6.0-7.0 | $1.50-$3.50 | Rim joists, crawl spaces, basements |
| Mineral Wool (Rockwool) | R-3.3-4.2 | $1.00-$1.80 | Fire-rated assemblies, sound insulation |
| Rigid Foam - EPS | R-3.6-4.4 | $0.75-$1.50 | Exterior continuous, slab edge |
| Rigid Foam - XPS | R-5.0 | $1.00-$2.00 | Below grade, foundations |
| Rigid Foam - Polyiso | R-5.7-6.5 | $1.25-$2.50 | Exterior walls, roof (R-value drops below 50F) |
Roofing Materials
| Material | Lifespan | Cost/sqft | Notes |
|---|
| Asphalt Shingles (3-tab) | 15-25 years | $1.00-$2.00 | Most affordable. Budget option. |
| Architectural Shingles | 25-30 years | $1.50-$3.00 | Standard residential. Better warranty and appearance. |
| Metal (Standing Seam) | 40-70 years | $4.00-$8.00 | Durable, energy efficient, fire resistant. |
| Slate | 75-200 years | $8.00-$15.00 | Premium. Very heavy, requires structural support. |
| Clay/Concrete Tile | 50-100 years | $5.00-$10.00 | Common in warm climates. Heavy. |
Window Types & Energy Ratings
- Double-pane (Low-E) — Standard for new construction. U-factor 0.25-0.30.
- Triple-pane — Cold climates. U-factor 0.15-0.20. Worth it in Zone 5+.
- Argon-filled — Inert gas between panes reduces heat transfer.
- Low-E coating — Reflects infrared heat. Low-E2 for cold, Low-E3 for warm climates.