Italian Window Tax Incentives 2027: Three Scenarios, and the Maths to Decide
Under current law the deductions fall. But the Government is considering raising them to 65%. Waiting risks €2,800 to gain €3,000 — and that is a calculation you can actually do.
Quick answer
For 2027 there are three scenarios, not one. Under current Italian legislation the window deduction falls from 50% to 36% on a primary residence and from 36% to 30% on other properties. The Government is however considering a strengthened energy deduction at 65% for primary residences, which would include window replacement. On €20,000 of work that means €10,000 of deduction by paying before December 2026, against €13,000 in the best case and €7,200 in the worst. Waiting therefore risks €2,800 to gain €3,000: you need roughly a 48% probability that the 65% passes for waiting to be worthwhile. To fall under the 2026 rates what counts is the cash basis — the date the transfer is ordered, not the end of the works.
Until a few weeks ago the customer's question was simple: "should I do the work now, before the deductions fall?". Since mid-September 2026 the question has changed, because a proposal has emerged for a strengthened energy deduction at 65% from 2027 — and now waiting might pay.
This article does not tell you what to do. It sets out the three possible scenarios, does the calculation that lets you choose between them, and explains the technical detail that decides the rate regardless of how the Budget Law turns out.
The three 2027 scenarios
On a window supply of €20,000 for a primary residence, here is what changes:
| Scenario | Rate | Deduction |
|---|---|---|
| Strengthened energy deduction (proposed) | 65% | €13,000 |
| Paying by 31/12/2026 | 50% | €10,000 |
| Current legislation, 2027 | 36% | €7,200 |
Between the best and worst scenario there is €5,800 at stake on the identical supply. The spending cap stays at €96,000 per property unit in all three cases, and the deduction remains split into ten equal annual instalments.
Is it worth waiting? The calculation nobody does
Industry articles stop at listing the three scenarios. But a customer who has to decide needs to know how much they have to believe in the 65% for waiting to make sense. It is arithmetic, and it takes one line.
Paying by December means taking home a certain €10,000. Waiting means betting between €13,000 and €7,200. In other words: you risk €2,800 to gain €3,000.
The break-even point is the probability p that makes the two choices equivalent:
p × 13,000 + (1 − p) × 7,200 = 10,000
which gives p ≈ 48%. If you believe the 65% energy deduction has more than a 48% chance of being approved, waiting pays. Below that threshold, paying by December is better.
It is not a number that says what to do: it is a number that makes the decision explicit rather than instinctive. And for a proposal that today has neither draft legislation nor a defined scope, 48% is a high threshold.
One consideration the arithmetic does not capture: someone who waits is not only postponing the deduction, they are postponing the energy savings of better windows and exposing themselves to another year of material price increases.
What is actually known about the 65% proposal
The proposal under consideration concerns the scope of the ecobonus, the Italian deduction for energy-efficiency works. According to press reports it would cover:
- window replacement
- thermal insulation and external cladding
- heat pumps and hybrid systems
- solar thermal and solar shading
- building automation systems
The higher rate would be reserved for the primary residence, with a differentiated and lower level for other properties. The funding would notionally come from European flexibility earmarked for energy-transition investment.
But the part that matters is what is not decided, which is almost everything: there is no draft legislation, no definitive list of eligible works, no spending caps, no start date. There are no institutional statements: these are press reports about a proposal under consideration. Everything will be set by the Budget Law, approved by the end of December.
A clarification worth passing to your customers. The 65% proposal concerns the ecobonus, not the general building bonus. Solar photovoltaic, for instance, falls outside it: it sits under the renovation bonus and follows a different curve. Anyone selling more than one type of work has to know the difference, because a customer who has read about the 65% will ask for it on things it does not apply to.
By when do you have to pay to fall under 2026?
This is the only point that does not depend on the Budget Law, and the one almost no quote communicates correctly. Italian building deductions work on a cash basis: the expense is considered incurred when the payment is ordered, not when the works finish and not when the bank debits the account.
- The transfer counts, not the building site. Works finishing in February 2027 still fall under 2026 if the payment was ordered by 31 December 2026.
- The order counts, not the debit. A transfer placed on 31 December falls under 2026 even if the value date is in January.
- It has to be a compliant transfer. Italian rules require a payment reference citing the legislation, the tax code of the person claiming, and the VAT number of the company. An ordinary transfer loses the deduction, regardless of the date.
It is the detail that answers the objection "the works will finish next year anyway, I will not make it in time" — which is false, and responsible for many November and December deals slipping. For the technical requirements on windows and the rates still in force this year, the reference is the 2026 window energy deduction.
The paradox: the proposal is already freezing the quarter
There is a side effect that directly affects anyone selling windows, and it is already under way. A measure designed to stimulate energy works, while it remains a proposal, pushes households to postpone precisely those works.
The result is that the last quarter — historically the period when customers move to use the incentives within the year — risks turning into a quarter of waiting. And the bill is not paid by the Government: it is paid by the companies that had those jobs in the pipeline.
Three things to do now, not in November:
- Put all three scenarios in the quote. Not two figures, three. A customer who sees the full calculation decides; one who only hears "hurry up" postpones out of distrust.
- Reopen stalled quotes with information, not pressure. Anyone who received a quote in the last twelve months has a right to know the picture has changed. It is the most credible way to restart a conversation: we cover it in quote follow-up for window companies.
- Prepare January now. Whatever comes out of the Budget Law, in January everyone will need contacting again with updated numbers. Whoever arrives with the list ready starts weeks ahead: how to fill January.
How to say it to the customer
The temptation is to pick a narrative and push it. Both versions — "hurry up" and "wait, the 65% is coming" — expose you to being contradicted in December. What holds up is the calculation:
"Your quote is €20,000. If the transfer goes out by December, you deduct €10,000 over ten years, and that is certain. If you wait, it depends on the Budget Law: with the 65% deduction being discussed you would reach €13,000, but if nothing passes it drops to €7,200. In practice you are risking €2,800 to gain €3,000, so waiting only pays if you think the 65% has better than a one-in-two chance. Today there is still no draft law. You decide — I will prepare the quote either way."
No promises and no invented deadline: a customer put in a position to decide. It is also the only version that withstands the follow-up question — "and what if they do approve it?" — because you have already accounted for it.
Note. This article is for information and commercial purposes and does not replace tax advice. The rates under current legislation are those in force in Italy as of September 2026; the 65% proposal is under consideration and, at the date of publication, has no draft legislation. Everything may change with the Budget Law. For a specific customer's case — technical requirements, combining incentives, ENEA filings — the reference remains their accountant.
In summary
Three scenarios, not one: 65% if the strengthened energy deduction passes, 50% by paying before December, 36% under current legislation. The break-even point is around a 48% probability, and for a proposal still without draft legislation that is a high threshold. The cash-basis rule remains the only certain element: what counts is the date the transfer is ordered, not the end of the works.
For a window company the real risk is not choosing the wrong scenario: it is standing still while customers wait. If you want to reach January with a flow of quote requests that does not depend on what the Budget Law decides, now is the time to build it — that is the work we do on marketing for window and door companies.
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