Cost guide
What attic insulation actually costs here
Nobody can price your attic over the phone. But you deserve a real range before you invite anyone over — here is ours, and what moves it.
About these numbers: the ranges below reflect typical installed pricing in the Metro Detroit market. Your quote comes from a free measured assessment of your actual attic, and it is the only number that means anything.
Blown-in cellulose top-up, by attic size
This is the common job — cellulose blown over existing insulation that is dry and clean, bringing the attic up to R-49 or better.
| Attic size | Typical range |
|---|---|
| Small attic Up to 800 sq ft — bungalow or small ranch | $1,400–$2,600 |
| Average attic 800–1,400 sq ft — most Metro Detroit homes land here | $2,200–$4,200 |
| Large attic 1,400–2,200 sq ft — larger colonial or two-story | $3,400–$6,500 |
Work priced separately
These are itemized rather than folded into a square-foot rate, so you can see exactly what you are buying and decline anything you do not want.
| Work | Typical range |
|---|---|
| Air sealing (before top-up) Sealing top plates, chases, can lights and the attic hatch | $450–$1,600 |
| Insulation removal Vacuum-out of contaminated, wet or rodent-damaged material | $1,200–$3,500 |
| Baffles and ventilation correction Keeping soffit vents clear so the new depth does not choke airflow | $300–$900 |
What moves your number
- How much you already have
- Topping up from R-19 costs less than topping up from nothing. We measure existing depth before quoting, because it changes the number more than anything else on this list.
- Whether air sealing is needed first
- Most pre-1980 attics need it. It adds cost up front and is the single thing that makes the insulation actually perform. We will tell you if you can skip it.
- Access
- A walk-up attic with decking is a different job from a 22-inch hatch in a closet ceiling. Low-slope roofs where nobody can stand up cost more in labor.
- Whether the old material has to come out
- Dry, clean fiberglass gets topped over — no removal, no demo. Rodent contamination, mold or water damage means removal first, which roughly doubles a typical attic job.
- Obstructions
- Knee walls, ductwork, recessed lights and bath fans all need handling before depth goes down. Common in Ferndale, Royal Oak and Berkley bungalows.
Now subtract the rebates
The number you pay is not the number on the quote. DTE pays up to $600 on qualifying insulation work, and the federal 25C credit covers 30% of qualifying cost against your taxes, capped at $1,200 a year.
On an average attic in the $2,200–$4,200 band, that is a meaningful share coming back. We file the utility paperwork and hand you itemized documentation for the tax credit. Full detail on the rebates page.
How to compare quotes without getting fooled
Insulation is easy to underbid because the customer cannot see what was skipped. Four questions separate a real quote from a cheap one:
- What R-value will I have after settling? Cellulose settles 10–20%. A quote promising R-49 at installation is promising R-42 by spring.
- Is air sealing included, and what does it cover? If it is not itemized, assume it is not happening.
- Are baffles included? Deep insulation without baffles buries the soffit vents and trades a heating problem for a moisture problem.
- Will you mark the depth? Ruler cards stapled to the trusses cost nothing and let you verify what you paid for.
A quote that is $400 cheaper and answers no to three of these is not a better deal.
When the cheapest option is doing nothing
If you already have ten or more inches of intact insulation and a reasonably sealed attic plane, the payback on more depth gets thin. We will tell you that at the assessment. Check it yourself first with the R-value guide — it takes five minutes and a ruler.
Cost questions
How much does attic insulation cost in Metro Detroit?
For a blown-in cellulose top-up, most Metro Detroit attics land somewhere between about $1,400 for a small bungalow attic and $6,500 for a large two-story, with the average home falling in the $2,200 to $4,200 range. What moves your number most is how much insulation you already have and whether air sealing is needed first.
Why is a top-up so much cheaper than a full replacement?
Because you are skipping demolition and disposal. Removing existing insulation means vacuum equipment, labor, bagging, hauling and disposal fees before a single inch of new material goes down. Topping up over dry, clean insulation avoids all of it and roughly halves the project.
Does air sealing really need to be a separate line item?
We price it separately so you can see what you are paying for, not to pad the total. It is genuinely additional labor — hours of crawling the attic plane finding and sealing penetrations before any material goes down. Contractors who bury it in the square-foot price are usually not doing it.
Should I get multiple quotes?
Yes, and compare what is actually in them rather than the bottom line. Ask each contractor: what R-value am I getting after settling, is air sealing included, are baffles included, and will you mark the depth. A cheaper quote that skips those three things is not cheaper, it is less.
Do you charge for the assessment?
No. We measure your existing depth, check the sheathing and ventilation, and give you a written number with the reasoning. If the outcome is that you do not need the work, that costs you nothing either.
Ranges last reviewed 2026-08-03.
Get your actual number.
Free measured assessment, written quote, and an honest answer about whether the work is worth it for your house.