GModG enacted: The new energy certificate arrives on 1 January 2027
GModG enacted: Heating reform since 29 July — new energy certificate from 1 January 2027. Timeline, changes and impacts for owners, managers, agents and platforms.
Author
Joost Jansky
Energy consultant, blogger
Joost Jansky writes for the Energyausweis blog about energy performance certificates in practice, building retrofit, and current legislation around the GEG, GModG and the EU Buildings Directive (EPBD). Focus: existing residential buildings, the difference between demand-based and consumption-based certificates, and realistic retrofit paths for owners.
Qualifications & experience
- Energy consultant focused on existing residential buildings
- In-depth knowledge of GEG, GModG and the EU Buildings Directive (EPBD)
- Specialities: demand-based and consumption-based certificates, building retrofit, realistic retrofit paths for owners
- Author on the Energyausweis blog
Contact
Articles by Joost Jansky
Building Modernization Act passed: What happens next for energy certificates?
The German Bundestag and Bundesrat have passed the GModG. What publication, timelines, and new energy certificate rules mean for owners — explained clearly.
GModG for Property Managers: Annual Consumption Data, Modernisation Recommendations and HOA Resolutions
Property managers and the GModG: annual consumption data over two years from the heating-cost-ordinance routine, quantified modernisation recommendations, and the HOA resolution risk explained for everyday practice.
GModG for marketing agencies: the energy performance certificate as lead lever and service stack for real-estate clients
Section 87 of the GModG hits real-estate listings and landing pages from 2027. How marketing agencies turn it into a lead lever, a service stack and mandate protection.
GModG for Property-Management Platforms: Integrating the Energy Certificate as a Platform Feature via API
The GModG turns the energy certificate into a platform feature: §§ 80, 82, 84 and 87 hit property managers directly from 1 January 2027. How SaaS platforms integrate via API — without an in-house consultant team.
GModG for Estate Agents: New Listing Rules, Handover and Fines from Entry into Force
What changes for residential estate agents under the GModG? Sections 80, 87 and 108 are rewritten — six fine offences, unfair-competition warning risk, new listing disclosure rules. A practical guide from 1 January 2027.
Consumption certificate: New choice for all residential buildings (GModG)
Consumption certificate for older homes: from 2027 the 1977 insulation rule falls away. Who benefits — and which annual data you still need under Section 82.
Energy certificate with MWh per year: Are the cards being reshuffled?
Energy certificate with MWh per year: what the GModG draft changes — and why class A+ is not the whole story. For homeowners.
Order a consumption certificate now – before the consumption-data rules change
Correction: 24 monthly values did not become law. What Section 82 really requires from 2027 — and when a consumption certificate in advance still pays off.
The A–G scale is coming — just not for your home: GModG fact check (originally cabinet draft)
GModG fact check (originally the cabinet draft of 13 May 2026): A to G for non-residential only; A+ to H stays for homes — confirmed in the promulgated Act. Obligations, fines and dates (Art. 2 from 1 Jan 2027).
GModG draft 2026: The quiet announcement of a major energy certificate reform
The government draft bill published on 5 May 2026 introduces targeted changes for energy certificates and signals a broader reform to come.
Key changes to energy certificates – overview and perspective
Energy certificates in transition: EU EPBD, Building Modernisation Act, new A–G scale and extended obligations. Overview for owners, agents and managers – with a European perspective.
Energy Certificate API: Legally Compliant Certificates for Your Online Portal – Without In-House Experts
How online portals offer legally compliant energy certificates: API integration, white-label, lead generation. One API for the full certificate lifecycle.
Will energy certificates become more comparable with the new A to G scale from May 2026?
Energy certificates with the A–G scale: why EU-wide comparability remains limited and where the certificate still adds value. For brokers and owners.
Energy certificate 2026: New A–G scale and extended duties
GEG 2026: Energy certificates are being re-evaluated. New A–G scale, extended duties and digital database. What owners need to know now.
Are energy certificate costs tax-deductible? How to save tax the right way
Energy certificate costs tax-deductible? ✓ Rental ✓ Sale ✓ §35a EStG ✓ All options and requirements at a glance. Save tax now!
20 clever prompts that pros use for energy certificates
Discover 20 proven ChatGPT prompts for energy certificate topics. For brokers, managers and property professionals – how to use AI effectively.
Free energy certificate? How to avoid paying for it
A free energy certificate is not possible, but you can avoid the cost. Three ways to save money and what to do instead.
Energy certificate for a single flat & mixed-use buildings: GEG requirements explained
Can you get an energy certificate for a single flat? When do mixed-use buildings need multiple certificates? All about § 79 and § 106 GEG explained.
Energy certificate cost: 10 online providers compared
Looking for a provider to create an energy certificate? We compared 10 online providers for you.
Energy certificate in Berlin: apply quickly and legally online
Find out how the building structure in Berlin and Brandenburg affects energy certificates for residential buildings, and how to apply for a certificate for your Berlin property quickly and in line with legal requirements online.
Documents for the energy certificate: what do I need?
What information and documents do you need to have an energy certificate prepared? We show you what to have ready.
The Energyausweis Smart™: how to increase your property’s value
The energy quality of buildings matters more and more. Find out how the Energyausweis Smart from energyausweis.de helps you increase your property’s value.
Understanding the energy certificate: a complete guide
Our guide explains all values and figures in the energy certificate and what you can do with them.
Energy certificate for your home: everything you need to know
Whether you are an owner, architect or agent – everyone knows the energy certificate matters. But what do you need to know about it?