After Section 25C: pricing a Cincinnati foam project in 2026

Corrected September 2026. An earlier version of this post described Duke Energy Ohio insulation rebates and CenterPoint Energy programs for Cincinnati homes. Neither is available to a typical Hamilton County household in 2026, so the math below starts over from what the rules actually say.

What the old credit was really worth on a foam job

Section 25C was worth less on spray foam than most people remember. It paid 30 percent of qualifying costs with a $1,200 annual cap, but for insulation and air sealing the IRS counted materials only; the labor to install them was excluded. On a spray foam invoice, where the crew, the rig, and the prep are a large share of the price, that trimmed the credit considerably.

A worked example. Suppose a 2025 attic job was invoiced at $6,000, and the itemized invoice showed $2,500 of foam and sealing materials. The credit was 30 percent of $2,500, or $750, not $1,200. If the materials line was not broken out at all, claiming even that took extra paperwork.

The same job in 2026

The credit will not be allowed for any property placed in service after December 31, 2025, per IRS guidance on the law that ended it. So the same $6,000 job finished in 2026 costs $6,000.

On the Ohio side there is nothing to subtract for a market-rate household. Duke Energy Ohio's efficiency spending under the rate plan the PUCO approved in May 2025 is a $7.2 million program for income-eligible customers over June 2025 through May 2028. CenterPoint Energy's Ohio gas territory is the old Dayton Power and Light gas system in western Ohio, not Hamilton County.

On the Kentucky side there is a small offset. Duke Energy Kentucky's Residential Smart $aver tariff caps the thermal envelope incentive at $250, and the work has to be done by a Duke Energy Kentucky participating trade ally. On the $6,000 example that is about 4 percent, useful but not a reason to change the scope.

The honest difference between 2025 and 2026 on a typical foam job is the materials credit you lose, often several hundred dollars rather than the full $1,200.

Where the return comes from now

With no credit, the payback is the energy bill. ENERGY STAR's estimate for sealing and insulating an existing home is an average savings of 15 percent on heating and cooling costs, with actual results depending heavily on how leaky the house was to begin with. That points 2026 money toward the work with the most leakage per dollar:

• Rim joists are small, cheap to foam, and leak badly in most pre-1995 houses here. See rim joist foam.
• Attic air sealing at top plates, chases, and hatches does more per dollar than adding depth on top of an unsealed floor.
• Knee walls and rooms over garages fix the rooms people actually complain about.
• Full roof-deck foam makes the most sense when an air handler or ductwork lives in the attic, and it is the most expensive per square foot, so it deserves the hardest look at the numbers.

Three things to do before signing in 2026

1. Ask for an itemized invoice anyway. Materials, labor, and prep on separate lines. It costs nothing, it documents the upgrade, and if a future program returns it will almost certainly ask the same materials question 25C did.

2. In Northern Kentucky, confirm the incentive before scheduling. Call Duke Energy Kentucky or check its current Smart $aver form, and confirm the company doing the work is a participating trade ally. After the fact is too late.

3. If your income may qualify, apply for weatherization first. Households at or below 200 percent of the federal poverty guidelines, or receiving SSI, can apply for the Weatherization Assistance Program, which can include insulation and air sealing. Waiting lists are common, so apply in the fall.

The bottom line

The credit is gone and the Ohio utility rebate is income-only, but the physics did not change: a leaky Cincinnati house still loses the same heat through the same gaps. Run your own square footage through the cost calculator, compare it against the 2026 incentives rundown, and see the cost FAQ for how board-foot pricing works. Then call or text us to talk through which piece of the house to start with.