Renovation tax credit: Section 35c on the service page

The tax reduction for energy-related work is neither a grant nor a refund but a deduction from the income tax assessed, which the owner applies for with the tax return. In the calendar year in which the work is completed and in the following year, the tax is reduced by 7 percent (§ 35c (1) EStG) of the costs each, by no more than 14,000 euros per year. In the third year the rate is 6 percent, capped at 12,000 euros. Together that comes to 20 percent of the costs. The annual caps are reached at costs of 200,000 euros (§ 35c (1) EStG), because 7 percent of that is exactly 14,000 euros. Per property the reduction is capped at 40,000 euros, even if several individual measures are carried out there one after another.

Unlike the tax relief for trade services, it is not only the labor costs that count. Eligible are the costs of professional installation, commissioning of systems, necessary ancillary work and the material costs directly linked to the measure (§ 1 ESanMV). The cost of the certificate itself is added on top. If the owner has hired an energy consultant approved by BAFA, the federal office for economic affairs and export control, to plan or supervise the work, the tax is reduced by 50 percent (§ 35c (1) EStG) of the consultant's fees, according to the tax authorities entirely in the year of completion (BMF, Einzelfragen zu § 35c EStG).

The conditions on the customer's side are quickly listed and cannot be checked by the firm. The building is located in the EU or the EEA, belongs to the taxpayer and is used by the taxpayer exclusively as a home in the year concerned (§ 35c (1) and (2) EStG). When the work is carried out, it must be more than ten years (§ 35c (1) EStG) old, counted from the start of construction. Eligible is work that started after 31 December 2019 and is completed before 1 January 2030 (§ 52 (35a) EStG).

Landlords are therefore excluded, and that affects a large part of the housing stock: 44.3 percent (Destatis, Zensus 2022) of occupied dwellings in residential buildings were occupied by their owners in 2022. A service page that mentions § 35c is therefore addressed specifically to owners who live in the house or condominium themselves. For condominiums the rules apply accordingly (§ 35c (5) EStG); costs relating to common property are usually allocated to the individual owners by the property manager according to their shares (BMF letter of 23 December 2024).

For the service page this means: the note on § 35c does not replace the note on § 35a. It is a second, separate piece of information for a narrower audience and for specific measures, and it only appears where those measures are offered.

Heating businesses should look closely at the list of systems that do not qualify. Heat generators based on gas, including gas condensing boilers and gas heat pumps, are excluded according to the tax authorities, just like oil and coal boilers; fuel cells and connection to a heating network are the exceptions (BMF, Einzelfragen zu § 35c EStG). Solar thermal systems, biomass heating, heat pumps and network connections can qualify, each with its own requirements. For heat pumps, biomass and fuel cell heating, the dwellings supplied must be heated with at least 65 percent (Annex 6 ESanMV) renewable energy after the work. Water-based heat pumps must reach a seasonal performance factor of at least 3.0 (Annex 6 ESanMV), and from 1 January 2028 (Annex 6 ESanMV) newly installed heat pumps must use natural refrigerants. How that fits with the deadlines of the EU F-gas regulation is covered in our article on the heat pump page and refrigerants from 2027.

The distinction is not a side issue. 56 percent (Destatis, Zensus 2022) of all dwellings in Germany were heated with gas in 2022, a further 19 percent with oil. In Lower Saxony the share of gas was 72 percent (Destatis, Zensus 2022). A heating page that speaks of a tax bonus for replacing the heating across the board raises an expectation among many readers that does not hold for the boiler they have in mind. The page therefore states for which systems the firm can issue the certificate and for which it cannot.

On many service pages the tax question appears, if at all, as an afterthought: subsidies possible, just ask us. That leaves the customer no wiser. What the customer wants to know is whether the paperwork needed afterwards will be provided, and that is exactly what the firm can promise without straying into tax advice. The tax question turns into a service promise: we carry out the work, document the minimum values and issue the certificate on the official form. 94 percent (Bitkom 2025) of the trade businesses surveyed use a website of their own. A firm that lists the same services there as the businesses down the road sets itself apart with a block like this on a point that means money to the customer.

What the block looks like depends on the trade. On a roofer's page it sits under roof renovation and states the values for pitched roof, flat roof and dormer; how we build such pages is described under web design for roofers. For joineries and window makers it belongs on the window page. There, the difference between a standard window and a low-barrier or burglar-resistant window deserves a line of its own, because the ordinance sets different maximum values for them. On the heating page of a plumbing and heating business it appears only next to the systems that qualify, not next to the gas condensing boiler.

The text promises nothing the firm cannot control. It names the provision, describes the firm's own service, mentions two conditions that lie with the customer and refers everything else to the right place. With small changes it fits the roofing, facade and heating pages, so a business with several trades maintains one shared base text and, per trade, its own lines for measures and values.

Three conditions of the tax reduction arise in the firm, not with the customer. The invoice must show the eligible measures, the labor of the qualified firm and the address of the property, and it must be issued in German; payment must go into the account of the service provider (§ 35c (4) EStG). The tax authorities accept bank transfer, direct debit, debit card and credit card with proof of the debit, but not cash payments or cash deposits, even if they were properly booked (BMF, Einzelfragen zu § 35c EStG).

The third point is completion. The reduction begins in the year in which the work is completed. It counts as completed when the service has been fully delivered, the final invoice has been issued and the amount has been paid in full into the firm's account; an agreed installment plan is not enough, a position the tax authorities base on a ruling of the Federal Fiscal Court (BMF, Einzelfragen zu § 35c EStG). Partial invoices for stages of a multi-part measure do not bring the start forward. For the service page this means: process and payment terms belong in the same section as the certificate, so the customer knows the order of events.

The basic rules for tax notes on trade websites apply here too: name the provision, describe the law instead of promising an outcome, refer to tax advisers and the tax office. With § 35c two particular points come on top. The amounts are considerably higher than with the trade services bonus, and most of the conditions lie with the customer: ownership, owner occupation, the age of the building, no other funding. A sentence such as “Save up to 40,000 euros” promises an outcome that depends on all of this and that the firm cannot influence.

Care is also needed with environmental claims. A sentence like “climate-friendly renovation with a tax bonus” mixes two claims, only one of which has a legal source. What now applies to general environmental claims on trade websites is covered in our article on eco claims on tradesperson websites. The block stays on solid ground as long as it sticks to what can be documented: measure, value, certificate.

Adding a § 35c block to existing service pages is not a big project if the pages are already separated by trade. For ongoing upkeep of existing pages there is our website maintenance from 49 euros per month net, cancelable monthly, with no minimum term. If that separation is missing, the block is a good reason to reorganize the service pages: we build a new website for trade businesses at a fixed price from 1,490 euros net with up to eight pages, and relaunch an existing website from 2,900 euros net. Hosting in Germany costs from 15 euros per month net, also cancelable monthly, with no minimum term. All amounts plus VAT, prices as of September 2026; the overview is on the pricing page.

What no agency can take over stays with the business: assigning its own measures, the certificate template, the evidence for each job and the procedures for invoices and corrections. We take care of the text, the structure of the service pages, the FAQ and upkeep with an as-of date.