Your Attic Is Probably Costing You Hundreds Every Year
Here’s a stat that surprises most homeowners: up to 25% of your home’s heating and cooling energy escapes through the attic. In Des Plaines and Schaumburg — where winters regularly hit single digits and summers push into the 90s — that translates to $300–$600 per year in wasted energy costs.
Proper attic insulation and weatherization isn’t glamorous, but it’s one of the highest-ROI home improvements you can make. At MMDS, we help homeowners across the northwest suburbs seal and insulate their homes for maximum comfort and minimum energy bills.
How to Tell If Your Attic Insulation Needs Upgrading
- Uneven temperatures — Second-floor rooms significantly hotter in summer or colder in winter than the main floor
- High energy bills — If your heating/cooling costs seem disproportionate to your home’s size
- Ice dams in winter — Ridges of ice forming at the roof edge indicate heat escaping through the attic
- Visible insulation below joists — If you can see the tops of floor joists in your attic, insulation is too thin
- Insulation age — If your Des Plaines or Schaumburg home was built before 2000 and the attic hasn’t been re-insulated, it’s almost certainly under current energy code standards
- Drafty rooms — Air leaks around fixtures, outlets, and attic access points
- HVAC system runs constantly — Your furnace or AC shouldn’t need to run nonstop to maintain temperature
Current Insulation Standards for Illinois Homes
Des Plaines and Schaumburg fall in IECC Climate Zone 5A. Current energy code requires:
| Location | Required R-Value | Equivalent Thickness (Blown Cellulose) |
|---|---|---|
| Attic (flat ceiling) | R-49 to R-60 | 14 – 17 inches |
| Cathedral ceiling/roof | R-38 to R-49 | Varies by method |
| Walls (new construction) | R-20 or R-13 + R-5 continuous | N/A (different products) |
| Rim joists/band board | R-15 to R-20 | Spray foam preferred |
| Crawlspace walls | R-15 | Rigid foam or spray |
Most homes built before 2000 have R-19 to R-30 in the attic — significantly below current standards. Upgrading to R-49 or R-60 delivers measurable energy savings and improved comfort.
Types of Attic Insulation: Pros, Cons, and Costs
Blown-In Cellulose
Made from recycled paper treated with fire retardant. Blown into the attic using specialized equipment.
- Pros: Excellent coverage, fills gaps and voids, eco-friendly, good soundproofing, cost-effective
- Cons: Can settle 15–20% over time (install slightly above target), absorbs moisture if roof leaks
- Cost: $1.00 – $1.50 per square foot (installed to R-49)
- Best for: Open attic floors, adding over existing insulation
Blown-In Fiberglass
Loose fiberglass fibers blown in similarly to cellulose.
- Pros: Doesn’t absorb moisture, doesn’t settle as much as cellulose, non-combustible
- Cons: Slightly less effective per inch (needs more depth), more expensive than cellulose
- Cost: $1.25 – $2.00 per square foot (installed to R-49)
- Best for: Moisture-prone attics, homeowners who prefer fiberglass
Fiberglass Batts
Pre-cut rolls or batts fitted between joists.
- Pros: DIY-friendly, predictable R-value per layer, readily available
- Cons: Poor performance if not installed perfectly (gaps, compression), doesn’t fill irregular spaces
- Cost: $0.75 – $1.25 per square foot (installed)
- Best for: New construction with uniform joist spacing
Spray Foam (Open-Cell and Closed-Cell)
Applied as liquid, expands to fill cavities completely.
- Pros: Air-seals and insulates simultaneously, highest R-value per inch (closed-cell: R-6.5/inch), moisture barrier (closed-cell)
- Cons: Most expensive option, requires professional installation, can trap moisture if improperly applied
- Cost: Open-cell: $1.50 – $2.50/sq ft; Closed-cell: $3.00 – $5.00/sq ft
- Best for: Rim joists, cathedral ceilings, knee walls, critical air sealing areas
Air Sealing: The Step Most Contractors Skip
Here’s the secret that separates effective weatherization from just “adding more insulation”: air sealing must come first. Insulation slows heat transfer through conduction, but it does very little to stop air movement. If warm air is leaking through gaps around:
- Recessed lighting cans (can lights)
- Plumbing and electrical penetrations
- HVAC duct boots and register cutouts
- The attic hatch or pull-down stairs
- Top plates of interior walls
- Chimney and flue chases
- Bathroom exhaust fan housings
…then adding insulation on top is like putting on a sweater with holes in it. At MMDS, we always perform air sealing before adding insulation. We use a combination of fire-rated caulk, expanding foam, metal flashing (for chimneys), and rigid foam board to seal every penetration.
The Weatherization Process: What to Expect
- Assessment — We inspect your current insulation type, depth, and condition. We check for moisture issues, pest damage, and existing air leaks.
- Air sealing — All penetrations, gaps, and bypasses are sealed before any new insulation goes in.
- Ventilation check — Proper attic ventilation (soffit vents + ridge vent or gable vents) is essential. We verify ventilation isn’t being blocked and install baffles at the eaves to maintain airflow.
- Insulation installation — Blown-in cellulose or fiberglass is installed to the target R-value. We place depth markers so you (and future inspectors) can verify coverage.
- Cleanup and documentation — We provide documentation of R-values achieved, which is valuable for home sales and utility rebate programs.
Rebates and Incentives for Des Plaines & Schaumburg Homeowners
- ComEd and Nicor Gas Rebates — Both utilities offer rebates for insulation and air sealing through the Illinois Home Weatherization program. Rebates can cover 50–70% of costs for qualifying households.
- Federal Tax Credit (25C) — The Inflation Reduction Act provides a tax credit of up to 30% of insulation costs (up to $1,200/year) for qualifying materials and installation.
- Illinois Home Performance with ENERGY STAR — Comprehensive weatherization program that includes a home energy audit and prioritized improvement recommendations.
We can help you navigate which rebates apply to your project.
Cost Summary: Attic Insulation Project
For a typical 1,200 sq ft attic (average Des Plaines/Schaumburg home):
| Component | Cost Range |
|---|---|
| Air sealing (comprehensive) | $500 – $1,200 |
| Blown cellulose to R-49 (1,200 sq ft) | $1,200 – $1,800 |
| Blown fiberglass to R-49 (1,200 sq ft) | $1,500 – $2,400 |
| Attic hatch insulation + weatherstrip | $75 – $200 |
| Baffle installation (soffit vents) | $200 – $400 |
| Typical total project (air seal + blown cellulose) | $1,800 – $3,200 |
With available rebates and tax credits, out-of-pocket cost can drop to $800 – $2,000. Payback period is typically 2–4 years through energy savings.
Frequently Asked Questions
Can I add new insulation on top of old insulation?
In most cases, yes. If the existing insulation is dry, free of mold, and not vermiculite (which may contain asbestos), new blown-in insulation can be added directly on top. We inspect existing insulation during our assessment and recommend removal only when necessary.
Will adding attic insulation make my house too tight?
Modern weatherization is designed to “build tight, ventilate right.” We ensure your attic maintains proper ventilation (soffit-to-ridge airflow) and your home has adequate fresh air exchange. If air sealing is extensive, we may recommend a mechanical ventilation solution like an ERV (energy recovery ventilator).
How long does attic insulation last?
Fiberglass and cellulose insulation can last 40–80 years if it stays dry and isn’t disturbed by pests or renovations. The main enemies of insulation longevity are moisture, compression, and animal activity.
Is it worth insulating if I’m planning to replace my HVAC system soon?
Absolutely — and it should be done first. Better insulation means your new HVAC system can be sized smaller (and cost less) while providing equal or better comfort. Insulate first, then size the HVAC system to the improved building envelope.
Get a Free Attic Insulation Assessment
MMDS serves Des Plaines, Schaumburg, and the surrounding northwest suburbs with professional insulation and weatherization services. We’ll assess your current insulation, identify air leaks, and provide a clear estimate — including any rebates you qualify for.
Financing available through Sunbit and PowerPay.
📞 Call (847) 221-6280 or request your free assessment online.