GModG enacted: The new energy certificate arrives on 1 January 2027

Joost Jansky

Energieberater, Blogger

What applies today — and what starts on 1 January 2027

On 28 July 2026 the amending act was promulgated in the Federal Law Gazette (BGBl. 2026 I No. 226). Since 29 July 2026, Article 1 and Articles 5, 6 and 8 apply: the Building Energy Act (GEG) becomes the Building Modernisation Act (GModG), and the heating rules change. Heating detail is out of scope here; the official portal summarises it under GModG updates.

For the energy certificate the distinction matters: “GModG in force” does not mean “new certificate immediately”. Until the end of 2026, certificates are issued under the interim rules — previous format, residential scale A+ to H, and the still-applicable consumption- and demand-based rules. The BBSR assigns the current reading version to 29 July 2026 to 31 December 2026.

Only Article 2 rewrites §§ 79 to 88 and implements the EPBD-aligned certificate reform. That article takes effect on 1 January 2027. For the path from parliamentary adoption, see GModG adopted: What follows for energy certificates?.

Timeline: When do you get the new energy certificate?

Article 9 of the amending act stages entry into force. For practice, this reading is enough:

Takeaway: You receive the new certificate type when the certificate is newly issued from 1 January 2027. A certificate from the 2026 interim period keeps its usual ten-year validity — it does not expire on New Year’s Day.

Practical example: Sale in autumn 2026 or spring 2027

If the notary appointment is still in 2026, an interim certificate is enough — and it remains usable for the usual term afterwards. If the transaction moves to January 2027 or later, a new issue follows the Article 2 format: expanded mandatory particulars, digital machine-readable format and — for non-residential buildings — the new A–G scale. Whether you order now or wait until 2027 depends mainly on when a sale or letting is due — and whether you still need a valid certificate before then.

What changes on the energy certificate from 1 January 2027

From Article 2 the EPBD-aligned certificate reform applies in the Building Modernisation Act. The overview bundles the points owners and professionals should know first.

The dual system remains only for buildings with exclusive residential use: demand-based under § 81 or consumption-based under § 82, if the data fit. “Residential building” under § 3 still means predominantly residential — for § 82 that is not enough from 2027: even a small commercial share (shop, practice, office) excludes a consumption-based certificate on the wording; then a demand-based certificate (§ 81) remains, often as a residential building with calculated non-residential portions.

From 2027 § 82 requires annual, energy-carrier-differentiated consumption data over two years; the most recent period may be no more than 18 months old. For non-residential buildings, choice disappears on sale, letting and comparable occasions: a certificate based on calculated energy performance must be issued.

Two often-overlooked property types: for listed buildings the former exemption from § 80(3)–(7) ends — issuance, presentation and handover duties apply from 2027 as for other buildings. The holiday-home exemption in § 2(2) no. 8 (short or strongly limited annual use) remains.

More on the scale logic: The A–G scale is coming — just not for your house. On choice for exclusive residential use: Consumption-based certificate: New choice for all residential buildings. Official certificate templates had not yet been published in the Federal Gazette at the time of this research; the BBSR portal Energy certificate templates announces they will be offered once published.

What this means for owners, sellers, landlords, managers, agents and banks

The same reform hits actors differently. The table gives the overview; below are the points that stick first in day-to-day work.

Homeowners

Without a sale or letting and with a valid certificate you need not reissue solely because of promulgation. If a new issue is due in 2027, choose for exclusive residential use between consumption and demand — if the consumption data meet § 82. For mixed use the path is demand-based. The residential scale remains A+ to H. Orientation: certificate check.

Sellers, landlords, tenants and viewers

On sale and letting the issue date counts. A 2026 certificate remains usable and steers listings via § 112(3). New issues from 1 January 2027 deliver the Article 2 format — including absolute energy amounts in MWh on the certificate.

Sellers need a valid certificate for marketing and the notary; from 2027 the new format, listing duty under § 87 and presentation at the viewing apply. Landlords face the same presentation and handover duties on new lets — and from 2027 also on lease extension if no valid certificate exists.

Viewers see different mandatory listing particulars depending on certificate age (old: final energy; new: among other things primary energy and issue date) and can inspect the certificate at the viewing. Tenants receive it on letting or extension; for older certificates the previous particulars and ten-year validity remain decisive.

Managers of multi-family buildings and condominiums

Managers often steer certificates for many units. From 2027 data-quality requirements rise (two annual periods, energy-carrier differentiation) and the distinction between exclusive residential use versus mixed use or non-residential. Digital output and modernisation recommendations touch software and owner communication — practical detail in GModG for property managers.

Estate agents and real estate professionals

From 2027 agencies must run two listing logics in parallel — steered by issue date, not by marketing year.

• Older certificate (before 01.01.2027): § 112(3) — among other things type of certificate and final energy demand/consumption, energy carriers; for residential buildings year of construction and class.
• New certificate (from 01.01.2027): § 87 — among other things § 81 or § 82, issue date, annual primary energy demand in kWh/(m²·a), class, year of construction, energy carriers.

Final energy drops from the listing duty but remains the basis of residential classes A+–H. Mixing the metrics risks fines and unfair-competition claims. Absolute annual amounts in MWh appear on the certificate (§ 85), not in the listing duty — but show up in exposé and financing talks. Presentation and handover under § 80 remain; lease extension can trigger a certificate. CRM and portal templates need separate “old / new certificate” fields. Detail and UWG risk: GModG for estate agents.

Banks and financing

Energy metrics already feed credit files and valuation. Heat summers, volatile energy prices and the EPBD agenda have raised the weight of energy performance for banks and valuers — as an indicator of running costs, lettability, renovation backlog and asset quality. GModG does not create a new “energy-class duty” for lending; from 2027 the new certificate does deliver more and more comparable data.

Lending: Poor efficiency, high annual MWh amounts or no renovation path can burden cost and default risk; proven modernisation supports the case. From 2027 read issue date and legal status — old and new certificates use different listing metrics.

Valuation: Absolute primary/final energy in MWh and greenhouse-gas figures make cost assumptions more tangible than area-specific values alone.

Renovation: Energy weaknesses are increasingly a value and risk factor. Certificate and modernisation recommendations provide a shared data basis for owners, bank and advisers — alongside checklists for two certificate generations and digital delivery formats.

Digital energy certificates in practice

From 1 January 2027 a newly issued energy certificate must be issued digitally in a machine-readable format (§ 79(2)). Paper is only available on request of the client or owner — not automatically for every interested party. The presentation duty on sale and letting (§ 80(4) and (5)) remains: at the latest at the viewing the certificate or a copy must be accessible; alternatively a clearly visible display or laying out is enough. How exactly to “show” a digital certificate on site is not spelled out in detail in the Act; official 2027 templates were still pending at the time of this research. What matters is that the content is accessible during the visit.

The graphic above summarises the flow; the three roles in brief:

Sellers and owners usually receive a digital file — store it, supply agent/notary, order paper only if needed. The presentation duty at the viewing remains; digital changes the medium, not the occasion.

Estate agents need the file in the property before the first appointment (tablet/PDF or printout). After contract: document handover. The larger substance challenge remains the two listing paths.

Property managers need room in software and filing for the machine-readable format — not only scanned legacy PDFs — plus owner access for letting and sale. Interfaces should deliver digital output and mandatory fields from 2027; see GModG for property managers.

Processes for professionals: When volume and mandatory fields rise

Platform operators, management software and agencies with high certificate volume hit the same date from 2027: DIN/TS 18599:2025-10, machine-readable output, expanded § 85 fields and listing logic. Anyone building norm calculation and template changes in-house needs a robust switchover window by the end of 2026.

Many therefore outsource issuance to an interface: UI and client relationship stay; calculation and format maintenance sit with the issuer backend. The Energyausweis API is built for that. Context: Energyausweis API for online portals and GModG for property-management platforms.

The earlier workflows map Article 2 fields and digital output, the quieter the year-end transition runs for teams with volume.

How to plan the transition to the new certificate type

1. Separate legal status and date. Since 29 July 2026 the name and heating reform (Article 1) apply. The new certificate type starts with Article 2 on 1 January 2027.
2. Inventory stock and occasions. Note issue date, expiry and planned occasions (sale, letting, extension, financing). Without transaction pressure and with remaining validity you need not reissue solely because of promulgation.
3. Prepare data and certificate type. From 2027: consumption only for exclusive residential use and with annual data over two years; mixed use and non-residential on transaction → calculation under § 81.
4. Plan 2027 duties. New issues follow § 87; older certificates follow particulars under § 112(3). Listed buildings are subject to the same certificate occasions as other buildings.
5. Check processes and interfaces at volume. Agencies, managers and platforms secure DIN/TS, digital output and mandatory fields — in-house or via an issuer API.

Overview — the essentials at a glance

• 29 July 2026: GModG name and heating reform (Article 1); certificates still interim.
• 1 January 2027: New certificate type on new issue (Article 2).
• Residential: A+–H; consumption only for exclusive residential use, otherwise demand; non-residential: A–G, calculation on transaction.
• § 82: only purely residential buildings; annual consumption data over two years; most recent period no more than 18 months.
• Older certificates remain valid; listings with older certificates follow § 112(3).
• Listed buildings: certificate duty from 2027 as for other buildings; holiday use under § 2(2) no. 8 still exempt where conditions are met.
• Digital: machine-readable issuance; at viewings screen, printout or display.
• Professionals at volume: embed mandatory fields and DIN/TS early in processes or an API.

Outlook and conclusion

The dates are set: heating and statute name since late July, new certificate type from New Year 2027. Owners can align the remaining validity of their certificates and planned sale or letting occasions with that calendar. Managers and estate agents should in parallel prepare data organisation and listing logic for older and new certificates. Banks and lenders, in turn, check how current their files are, as well as the legal status and the issue date — not only the class on the cover page.

What remains open is mainly the official templates and software fine-tuning — that does not change the effective date. Anyone issuing from 1 January 2027 must meet Article 2. Anyone wanting a forward-looking transition should inventory planned occasions and existing certificates now and gather consumption data early if a consumption-based certificate may apply. At higher certificate volume it also pays to look at processes and the technical delivery chain (software, interfaces, mandatory fields), so the 2026/27 year-end switch runs reliably.