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Do You Need a New Roof Before Solar in Illinois? (2026 Roof-Age Rules)

Ryan Cook•July 12, 2026•Updated Sep 16, 2026

You need a new roof before solar only if the roof has less than about 10 years of life left. More than 15 years left, install now. Somewhere in between, get it inspected first. The reason is the bill for doing it in the wrong order: taking a home system down and putting it back for a roof job runs an estimated $2,800 to $6,000, and in Illinois the panels earn nothing toward your Illinois Shines production payments while they sit in the driveway.

That's the whole answer. Here's why the number is what it is, and how to sequence the two jobs so you only pay once.

Asphalt shingle roof on a central Illinois home in late afternoon light, showing weathering and age

The rule: it's remaining life, not age

Age by itself tells you almost nothing. A 14-year-old roof in decent shape and a 14-year-old roof that took a hail beating in 2023 are two completely different situations. What matters is how many years it has left.

Here's the framework I use, and it's the one most reputable installers use too:

More than 15 years of life left — go ahead. Install solar now, no roof work needed.
Roughly 10 to 15 years left — get it inspected. Don't guess, and don't let a solar salesperson be the one who decides.
Under 10 years left — replace the roof first, then put panels on the new surface.

The logic is just arithmetic. Solar panels are built to run an estimated 25 to 35 years — that's the Department of Energy's current figure. Most Illinois homes wear asphalt shingles, which last somewhere in the 15-to-30-year range depending on the product and how much weather they've eaten. If the roof quits before the panels do, every one of those panels has to come down and go back up.

What that mistake actually costs

Taking a system off and putting it back runs an estimated $225 to $300 per panel. A typical home system of 15 to 20 panels lands somewhere around $2,800 to $6,000 — and that's just the panel handling. The roof itself is a separate bill on top.

The work usually eats about a week: one to two days to disconnect and pull the array, then two to three days to remount and rewire after the new shingles are down.

Those are industry estimates, not a quote — the real number depends on your system size, roof pitch, and who's doing the work. But it's real enough that I've watched it change people's minds at the table.

What	Figure	Basis
Install solar now	Roof has 15+ years of life left	My rule of thumb, shared by most reputable installers
Inspect first	Roof has roughly 10–15 years left	Same
Replace the roof first	Roof has under 10 years left	Same
Remove and reinstall a home system	Est. $2,800–$6,000 (about $225–$300 per panel, 15–20 panels)	Industry estimates, 2026; your quote will vary
Time the panels are down	About a week (1–2 days off, 2–3 days back on)	Industry estimates
Panel working life	Est. 25–35 years	U.S. Department of Energy
Illinois Shines REC contract	15 years, paid on actual production	Illinois Power Agency
Summer Price to Compare, June 1–Sept 30, 2026	Ameren Illinois 11.326¢/kWh · ComEd 10.399¢/kWh (supply only)	plugin.illinois.gov

The Illinois wrinkle nobody mentions

Here's what the national roofing guides leave out, and it's the part that actually matters here.

Illinois pays you for solar through Illinois Shines, and those payments are tied to production — the actual kilowatt-hours your panels generate — across a 15-year contract. That's the REC money that makes the numbers work in this state.

Think about what a roof replacement in year seven does to that. Your panels sit in a driveway for a week. They generate nothing. You're buying every kilowatt-hour from Ameren or ComEd at full summer rates — 11.326¢/kWh and 10.399¢/kWh respectively for supply through Sept 30, 2026, and closer to an estimated 19¢ and 17¢ all-in once delivery is stacked on. (Both supply prices reset October 1.) And the production you didn't make is production you don't get credited for.

A cost question in Kansas is a cost-and-income question in Illinois. That's a meaningful difference, and it's why I push sequencing harder here than a salesperson in a state with no REC program would.

If you're on a lease, the panels aren't yours

This one surprises people, so I'll say it plainly. Under a lease or a power purchase agreement, a third party owns the hardware on your roof. That's the whole point — it's why you paid nothing down.

Which means you can't just call a roofer and have them pull the panels. You contact the system's owner, get approval in writing, and use a crew they authorize, on a timeline that suits them. Most agreements allow the work. Some attach a removal-and-reinstall fee. None of it is a scam, but it's friction you don't want in the middle of a leak.

The fix is boring and it works: do the roof first, then start the lease. The problem evaporates. If you're already under contract, pull out your agreement and read the removal clause before anyone climbs a ladder. Our breakdown of how solar leases work in Illinois covers what else lives in that paperwork.

Hail country changes the calculus

If you're in Peoria, Pekin, Bloomington, Normal, or anywhere else in the central Illinois hail belt, you already know roofs age faster here than the brochure says.

That cuts both ways, and the good direction is genuinely good: if a storm claim is already paying for a new roof, that is the single best moment in your life to go solar. The shingles are coming off regardless. Insurance is handling the roof. You put panels on a brand-new surface, and you never pay a removal bill — not in year seven, not ever.

I've had customers stumble into that timing by accident. It's a much better plan on purpose.

Doing both at once is the cheap way

When the roof and the solar happen as one project, you skip the $2,800-to-$6,000 removal bill entirely, because it never comes due. You also collapse two sets of permits, two setups, and two crew mobilizations into one — industry estimates put that duplication at roughly $500 to $2,000.

That's the whole reason we handle roofing and solar together instead of pretending the roof is someone else's problem. It isn't. It's the surface the entire 25-year investment sits on.

What to actually do this week

Start with the roof, not the panels. Get someone who works on roofs for a living to tell you remaining life in years — not "it looks fine," not a pass/fail. That single number decides everything downstream.

Then run your numbers. If the roof is solid, our savings calculator will show you what a system does against your current Ameren or ComEd bill, and the real cost of solar in Illinois post lays out where the money actually goes. If you want a fast read on whether your roof is even a candidate, check my roof uses satellite imagery to give you a first look without anyone knocking on your door.

If the roof is tired, that's not a no. It's a sequence. Fix the surface, then put the panels on it once.

Sources

Either way, I'd rather tell you to wait six months and do it right than sell you a system today that costs you six thousand dollars in year seven. Call me at (618) 217-2001 or reach out here and I'll tell you straight which situation you're in.

Frequently Asked Questions

It depends on how much life your roof has left, not on how old it is. The rule I use: if your roof has more than 15 years of remaining life, go ahead and install solar now. If it has roughly 10 to 15 years left, get it inspected and decide with real information. If it has under 10 years left, replace it first. The reason is simple math. Solar panels last an estimated 25 to 35 years by the Department of Energy's count, and most Illinois homes have asphalt shingles that last 15 to 30 years. If the roof gives out first, someone has to take every panel down and put it back up — and that runs an estimated $2,800 to $6,000 on a typical home, roughly $225 to $300 per panel. That's money you spend twice for no extra power.

Industry pricing generally runs an estimated $225 to $300 per panel, which puts a typical 15 to 20 panel home system somewhere around $2,800 to $6,000 — and that's before you pay for the roof itself. The job usually takes about one to two days to disconnect and pull the panels, then another two to three days to remount and rewire them after the new roof is finished. Those are estimates and your quote will vary. Two things make it worse than the sticker price. Your system produces nothing while it's on the ground, so you're back to paying full utility rates during the gap. And in Illinois, your Illinois Shines payments are tied to what your panels actually produce, so downtime can cost you on that side too. Get the removal number in writing before anyone starts, because a verbal estimate has a way of growing once the panels are already off the roof.

Physically, usually yes — a structurally sound roof will hold panels regardless of its age. Whether you should is a different question. A crew can mount panels on a 16-year-old asphalt shingle roof without much trouble, and plenty of companies will happily do it, because the roof is not their problem after the install. It becomes your problem in year six or seven when a leak shows up and the panels have to come off. Before you sign anything, get the roof looked at by someone whose job is roofs, not panels. Ask for remaining life in years, not a pass or fail. If the honest answer is under a decade, do the roof first and go solar on a clean surface. If you'd rather skip the roof question entirely, a ground-mounted system is worth pricing out.

This is the part people miss. With a lease or power purchase agreement, the panels on your roof are not yours — a third party owns them. You can't hire your own roofer to pull them off and toss them in the garage. You have to contact the system's owner, get written approval, and use a crew they authorize, on a schedule that works for them. Many contracts allow it, and some charge a removal and reinstall fee for the trip. It's not a trap, but it is friction, and it can stall a roof job for weeks while you wait on approvals. The clean way around all of it is sequencing: handle the roof before the lease starts, and the question never comes up. If you're already mid-lease, read your agreement's removal clause before you call a roofer.

Generally yes, and the savings come from two places. First, you avoid the remove-and-reinstall bill entirely — that's an estimated $2,800 to $6,000 you simply never pay, because the panels go onto a brand-new surface the first time. Second, doing both jobs in one project means one round of permits, one setup, and one crew mobilization instead of two, which industry estimates put at roughly $500 to $2,000 in avoided duplicate costs. There's a timing angle too. If hail or wind damage already has your insurance paying for a roof replacement, that's the single best moment to add solar, because the roof is coming off anyway and the panels land on new shingles. Ask whoever quotes your solar whether they can coordinate the roof work directly, since one point of contact beats refereeing two crews who each blame the other. I'd rather sequence a customer properly and wait a month than watch them pay for the same work twice.