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From the GEG to the Building Modernisation Act

📐 Article5 min read

What you will learn When the new act entered into force, which provisions apply immediately and which follow later, what replaces the renewable energy obligation, and what criticism accompanied the process.

The Building Energy Act has been superseded. Since 29 July 2026 the Gebäudemodernisierungsgesetz, Building Modernisation Act, applies, replacing the former title and reordering the requirements on heat supply in buildings.

The changeover proceeds in stages. Anyone designing today therefore works partly with law in force and partly with law yet to take effect.

The course of the process

Date Step
13 May 2026 Government draft adopted by the federal cabinet
8 July 2026 Adopted with amendments in the economics and energy committee
10 July 2026 Passed at second and third reading in the Bundestag; Bundesrat approval the same day
28 July 2026 Promulgated in the Federal Law Gazette
29 July 2026 First provisions entered into force

The Bundestag vote was recorded: 322 members in favour, 272 against. The Bundesrat declined to convene the mediation committee.

The act enters into force in stages

This is the point that matters most in practice and the one most often abbreviated. It concerns which provision applies at which date.

Stage What applies
Since 29 July 2026 the provisions on heat supply, in particular the removal of the previous renewable energy requirement
At later dates individual provisions take effect from 1 January 2027 and later, according to the available information
Not yet in force the provisions transposing the European buildings directive

A checking question therefore arises on every project: which provision applies at the relevant date, and which applies only later. The allocation must be established case by case.

What replaces the renewable energy obligation

The core of the reform is a change of direction in heating regulation. Four elements make it up together.

Element of the change Content
The uniform requirement falls away the obligation for newly installed heating systems to use a minimum share of renewables is repealed
Technology choice becomes free heat pumps, district heating, hybrid solutions, biomass and further options stand side by side
A staged obligation takes its place from 2029, progressively rising shares of climate-neutral fuels apply
Implementation of that quota is outstanding the federal government must present a separate act for it by 1 December 2026

For advisory work the shift means the risk moves from the investment decision to running costs. Anyone installing a fossil heat generator today is choosing a system whose fuel costs will be subject to future quota requirements.

Further changes

Three points matter for design and asset management. They concern costs, building services and inspection duties.

Point Content
The allocation of carbon costs is recast for new gas heating, further components join the emissions themselves
Mechanical ventilation with heat recovery is recognised as a compliance option a long-standing request from the sector
Inspection duties are extended ventilation systems above a capacity threshold now fall within them

The criticism of the process

A fair account of this act would be incomplete without noting the criticism that accompanied it. Three points recur in that criticism.

Criticism Content
The process was unusually short only a few days were allowed for comments on the draft
The criticism came from several directions those commenting included the Bundesrat and the national regulatory control council
The Bundestag simultaneously adopted a resolution calling on the federal government to act at European level

These points matter beyond politics. They suggest that further amendments are to be expected.

What follows for cost work

Three consequences are foreseeable.

Consequence for cost work What follows
Benchmarks from before the reform need checking a benchmark presupposing a particular form of heat generation does not reflect the new position
Funding must be considered separately funding continues and is being adjusted according to government statements
Running costs gain weight where the investment decision becomes freer and fuel requirements bite in stages, risk shifts into operation

This article reflects the position of the legislation at the date of checking and serves professional orientation. It does not constitute legal advice and does not replace assessment of the individual case.

Frequently asked questions

It takes the place of the previous framework and applies in stages. The article describes the legislative process.

The article describes what takes its place and from when. The stages have different dates.

The article names them and places their reach. They concern certificates and deadlines.

At the process and the shortness of the transitional periods. The article presents it factually.

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