New A to G scale from 2027 — but only for non-residential buildings

On 1 January 2027 the energy performance certificate (Energieausweis) of a non-residential building (Nichtwohngebäude) gets a letter for the first time. Anyone who owns or manages an office, retail, hotel, surgery, warehouse or production building will in future find an efficiency class from A to G there — seven levels, laid down in the new Annex 10a of the Building Modernisation Act (Gebäudemodernisierungsgesetz, GModG). The amendment was promulgated in the Federal Law Gazette on 28 July 2026; its energy certificate part enters into force on 1 January 2027.1

For residential buildings nothing changes at this point: they keep the nine-level scale A+ to H, and with unchanged class limits.13 The confusion is understandable: two scales, one amendment, one cut-off date.

#What is new

This is about § 86 of the Building Modernisation Act: from 2027 it is simply titled “Energy efficiency classes” and gains two paragraphs. Paragraph 3 requires the energy performance certificate to state the efficiency class of the non-residential building as well, classified according to the new Annex 10a. Until now § 86 has prescribed the class only for residential buildings;2 the certificate for a commercial property today carries key figures, but no letter.

Owners are more likely to feel a second change: if a non-residential building is to be sold, let, leased or leased out — or if such a contract is extended — from 2027 an energy performance certificate based on an energy balance calculation must be issued, in other words a demand certificate (Bedarfsausweis). This only applies if there is no valid certificate for the building.1 How the two certificate types differ is explained in Consumption certificate or demand certificate.

The classification follows its own logic. For residential buildings an absolute value in kilowatt-hours per square metre and year decides. Here it is a ratio without a unit: the calculated primary energy demand divided by the demand of a reference building of the same construction and use, for which, under § 86 (4) sentence 2, the primary energy factor 0.7 always applies1. A value of 2.0 therefore means: roughly twice the reference building.

Alongside the calculation there is a hard condition: only a zero-emission building gets class A — one that causes no on-site emissions from the use of fossil energy. A gas boiler therefore rules out class A, regardless of the figure. This condition was only added during the parliamentary procedure, together with the final class limits: the Committee on Economic Affairs and Energy replaced the values in the government draft.6 Older texts based on the cabinet draft therefore give different figures. Both go back to the European Buildings Directive: according to the explanatory memorandum, the new paragraphs transpose its Article 19 (2).5

#What this means in practice

#Non-residential buildings: the letter is a yardstick

The new § 40 limits the annual primary energy demand of existing non-residential buildings: from 1 January 2030 to 3.5 times, from 1 January 2033 to 2.95 times that of the reference building.1 These are exactly the lower limits of classes G and F in Annex 10a — the letter in the certificate is therefore not a label but the quantity against which the requirement is measured.

§ 40 (3), however, withdraws the requirements insofar as compliance is technically impossible or economically unreasonable, and they are deemed met for buildings constructed from 1996, for proven upgrading to the level of the 1994 Thermal Insulation Ordinance and for mainly heating with biomass, a heat pump or district heating. Listed buildings, foreseeable demolitions and industrial plants with low energy demand also remain outside.

How many buildings is the government targeting? The draft Act counts around 294,000 non-residential buildings in class G — the worst sixth of the stock, measured at the 2020 position — that must act by 2030, and a further 185,000 in class F by 2033 — together 479,000 of 1.84 million buildings addressed, exemptions already taken into account. According to the same explanatory memorandum, this number falls by around 30 per cent by 2030 because electricity and district heating become cleaner, and by a further 10 per cent or so through modernisation.5 The Institut Wohnen und Umwelt counts around 1.98 million buildings that fall fully under the Act.7 The two counts start from different points and cannot be set against each other.

Many owner-occupied non-residential buildings have no energy performance certificate today; the German Property Federation (Zentraler Immobilien Ausschuss) therefore expects market bottlenecks and price peaks.8 Anyone who wants to sell or re-let in 2027 would do well to plan the demand certificate early — it is the more demanding of the two types, as What an energy performance certificate costs shows using the prices for residential buildings.

#Residential buildings: A+ to H, unchanged

The amendment changes nothing about the scale for residential buildings. The amending Act only adjusts the heading there and the designation of the reference area in the second column, which in future refers to DIN/TS 18599: 2025-10. Annex 10 keeps its nine classes from A+ to H, and the class limits stay put figure for figure.1

The Act contains no renovation duty for individual residential buildings: § 40 speaks only of non-residential buildings, even in its heading. An adjustment of Annex 10 is announced in the explanatory memorandum, but has neither been scheduled nor adopted.5

#Frequently asked questions about the new scale

#Conclusion: two scales, one cut-off date

From 1 January 2027, energy performance certificates for non-residential buildings carry a class from A to G, calculated as a ratio to the reference building; class A is reserved for zero-emission buildings. Residential buildings keep A+ to H with unchanged limit values. From 2030 and 2033, § 40 measures its renovation requirements against the same values.