Upgrading your home’s insulation and electrical wiring can improve comfort, energy efficiency, and safety. But what does it actually cost? The answer depends on house size, material choices, labor rates, and whether both upgrades are done together or separately. This guide breaks down the real costs, hidden fees, and how to estimate your own project.
Why Upgrade Insulation and Wiring?
- Insulation reduces heating and cooling bills, improves comfort, and can raise resale value.
- Wiring upgrades improve safety, bring your home up to modern code, and support today’s power-hungry appliances.
- Doing both at the same time can save on labor, since contractors may already be opening walls or attics.
Main Cost Drivers
Several factors affect the total project cost:
- Square footage of attic, walls, or crawl space to insulate
- Type of insulation: fiberglass, spray foam, blown-in cellulose, mineral wool
- Accessibility: open walls vs closed cavities
- Wiring condition: full rewire vs partial update
- Electrical panel: whether a service upgrade is needed
- Permits and inspections required by local building codes
- Finishing work: patching drywall, painting, or replacing trim
Insulation Upgrade Costs
Average installed costs in 2025:
| Insulation Type | Cost per Sq. Ft. (Installed) | Notes |
|---|---|---|
| Fiberglass batts | $1.00 – $2.00 | Affordable, good for open walls or attics |
| Blown-in cellulose | $1.50 – $3.00 | Great for retrofits; fills cavities |
| Spray foam (closed-cell) | $3.50 – $7.00 | High R-value, expensive but efficient |
| Rigid foam board | $2.00 – $5.00 | Often used for basements or exterior walls |
Example: Adding attic insulation in a 1,200 sq. ft. home may cost $2,000 – $5,000 depending on material.
Wiring Upgrade Costs
Rewiring depends on home size, accessibility, and panel capacity. Typical 2025 costs:
| Home Size | Average Cost Range | Per Sq. Ft. Benchmark |
|---|---|---|
| Small home (1,000 sq. ft.) | $4,000 – $9,000 | $4 – $9 per sq. ft. |
| Medium home (1,500–2,000 sq. ft.) | $8,000 – $18,000 | $6 – $10 per sq. ft. |
| Large/older home (2,500+ sq. ft.) | $15,000 – $30,000+ | Higher due to complexity |
Additional costs:
- Panel upgrade: $1,500 – $4,000
- Outlet/switch additions: $100 – $200 each
- Drywall repair and painting: often extra
Combined Project: Insulation + Wiring
If you’re opening walls for wiring, it often makes sense to add insulation at the same time. While total costs add up, you may save 10–15% on labor and avoid duplicate demolition.
Example:
- Insulation upgrade (attic + walls): $6,000
- Whole-house rewiring: $12,000
- Combined project cost: ~$16,000 – $17,000 instead of $18,000+ separately
Hidden Costs to Plan For
- Removal of old insulation (can add $1,000 – $2,000)
- Hazard mitigation (asbestos, knob-and-tube wiring)
- Permit and inspection fees ($500 – $2,000)
- Temporary accommodation if power is off for several days
Always add a 10–20% contingency buffer to your renovation budget.
How to Estimate Your Own Costs
- Measure the spaces to be insulated (attic, crawl space, walls).
- Note the age of your wiring and whether a panel upgrade is needed.
- Choose insulation type and electrical capacity upgrades.
- Multiply square footage by average per-sq. ft. costs.
- Get 2–3 contractor quotes for accuracy.
- Use an online tool like House Cost Estimator to refine your numbers.
Example Scenarios
- Scenario 1: Small attic + partial rewiring → $6,000 – $8,000
- Scenario 2: Full attic + wall insulation + whole-house wiring → $18,000 – $25,000
- Scenario 3: Luxury upgrade with spray foam + panel upgrade → $25,000 – $35,000+
FAQs: Cost of Insulation and Wiring Upgrades
How much does insulation upgrade cost per square foot?
Most range between $1 – $7 per sq. ft., depending on material.
What is the average cost to rewire a house in 2025?
Between $8,000 – $20,000 for most medium-sized homes.
Is it cheaper to do wiring and insulation together?
Yes, you can save 10–15% in shared labor costs.
Do I need permits for rewiring and insulation?
Yes, permits and inspections are usually required for electrical work; insulation may also require approval in some areas.
What hidden costs should I budget for?
Drywall repairs, permit fees, old material removal, and contingency for surprises.
Final Thoughts
The cost of upgrading house insulation and wiring varies widely, but planning ahead helps prevent budget surprises. Expect insulation to cost a few thousand dollars, and rewiring to cost in the tens of thousands for a full house. Doing both at once often saves money and reduces disruption.
👉 For a tailored estimate based on your location and project scope, try the House Cost Estimator before you start planning.