Order a consumption certificate now – before 24 months of data become mandatory

Joost Jansky

Energieberater, Blogger

Note: This article is based on the cabinet draft of the Building Modernisation Act (GModG) of 13 May 2026. Until promulgation, the German Building Energy Act (GEG) applies unchanged; amendments are possible in the parliamentary process.

In brief: GModG draft and consumption certificate

The consumption-based energy certificate remains envisaged for purely residential buildings in the draft – it is not abolished. What is tightened is mainly the data basis and calculation methodology behind the rating. Where a folder of annual statements often sufficed until now, the draft requires a continuous monthly series and normalisation that compares actual heating behaviour with typical residential use.

Three points separate the debate from confusion with non-residential buildings:

1. Residential only: The draft limits certificates based on recorded final energy consumption (future Section 82 GModG) to buildings used exclusively for residential purposes.
2. Non-residential buildings: On sale, letting or lease renewal, only a certificate based on an energy balance (Section 81 in the draft) is to be issued for non-residential buildings – the consumption certificate ceases on re-issue there (Section 80(3) sentence 2 GModG draft, see cabinet draft).
3. Timing: According to the explanatory memorandum, the energy certificate rules in Article 2 of the draft are to enter into force six months after promulgation – not on the day of the cabinet decision (see cabinet draft).

The fact check on the GModG cabinet draft places the full draft in context.

The key distinction: this is not about blanket invalidation of existing certificates. The central question is whether a consumption certificate can still be issued with today’s effort – or whether owners are effectively steered towards the more demanding demand certificate. The draft and reference draft also announce a comprehensive reform of energy certificate law: for homes the consumption certificate remains on paper, but its practical availability is no longer secure long term.

From three billing periods to 24 monthly values

The tightening is clearest in data requirements: from three billing periods to 24 monthly values.

Today: billing periods instead of a monthly matrix

Under Section 82(4) GEG, a consumption certificate requires consumption data from at least three consecutive billing periods within a continuous period of generally 36 months. The most recent period may be at most 18 months old. In practice, many owners of detached and smaller multi-family homes manage with annual heating cost statements or supplier bills – without monthly breakdown by energy carrier.

Practical example (today): A detached home with gas heating. Three annual supplier statements (2023–2025) are available – under GEG a consumption certificate can often be produced without collecting monthly meter readings.

Draft: 24 months, monthly, by energy carrier

Section 82(1) sentence 2 of the GModG draft provides that final energy consumption is to be recorded differentiated by energy carrier, at least monthly over 24 consecutive months. This implements Annex I of EU Building Directive 2024/1275 (see draft explanatory memorandum).

In addition, the most recent billing period in the draft may only be 15 months old (Section 82(4) GModG draft) – a further tightening compared with today’s 18 months under Section 82(4) GEG.

Consequence: Anyone who can only submit annual statements will probably no longer receive a consumption certificate under the draft unless monthly values split by carrier exist. Then the demand certificate remains – with higher data effort and without today’s consumption history.

Practical example (draft): The same stack of statements is insufficient if only annual totals are shown. Twenty-four monthly values would be required, separated for gas for heating and, where relevant, electricity for hot water or auxiliary energy. If they are missing, the consumption option disappears – regardless of the building’s energy condition.

Checklist: is the data available?

• Are consumption values available for the whole building (not just one flat)?
• Are values available monthly – or only as annual totals?
• Can heating and, if applicable, hot water be assigned to energy carriers (gas, oil, district heat, electricity)?
• Do the data cover 24 consecutive months?
• Is the latest period still within the deadline (18 months today, 15 in the draft)?

If any answer is “no”, a consumption certificate after entry into force of the tightened Section 82 will probably only be possible with considerable metering or IT effort – or effectively no longer at all. For re-issues, only the demand certificate often remains; it is more burdensome to prepare and may show a less favourable efficiency class.

Even complete monthly data do not end the calculation. That leads to the second tightening: methodology behind the rating.

Weather adjustment and normalisation

Monthly consumption values are the first requirement. Section 82(3) of the GModG draft also requires:

1. weather adjustment of recorded final energy consumption, and
2. normalisation to boundary conditions of use for residential buildings under DIN/TS 18599-10:2025-10 Table 5 – with due regard for occupant behaviour including longer vacancy.

Today, Section 82(5) GEG and the announcement of rules for energy consumption values in the residential stock (of 29 March 2021, Federal Gazette) mainly govern climate factors (degree-day reference, Potsdam location) and vacancy adjustment – without an express reference to DIN Table 5 for homes.

The draft links consumption certificate logic for the first time expressly to the norm family that describes standardised use for the demand certificate. Section 7 of DIN/TS 18599-10:2025-10 contains reference climate monthly values – consistent with monthly recording in subsection 1, even though the law does not expressly name “monthly weather adjustment”.

The future calculation procedure in the Federal Gazette (Section 82(5) draft) will have to close this gap. Currently, the 2021 procedure still applies.

What “boundary conditions of use” mean for you

Normalisation in subsection 3 refers to Table 5 of DIN/TS 18599-10:2025-10 – not the detailed use profiles in Annex A (office, school, hall) that mainly concern non-residential buildings. For homes it is about typical residential use reference values.

These include room temperatures and setback in reduced operation, use and operating times, occupancy and internal heat gains, ventilation and boundary conditions for domestic hot water.

For the result this has tangible effects:

With economical heating (low room temperature, short heating periods), the stated consumption after normalisation may be higher than everyday use. Longer vacancy was already limited through vacancy factors; the draft additionally anchors this via occupant behaviour and Table 5. A “good” consumption result will reflect typical residential use more strongly – not individual thrift alone.

Practical example: A terraced house ready for sale is heated to 18 °C. Measured gas consumption is low; after normalisation to typical residential boundary conditions the rating may be worse than buyers expect from how the home feels. Conversely, a permanently overheated rental block may look better after adjustment than tenants’ real consumption – a reason to make certificate type and methodology transparent on issue.

Anyone who preferred the consumption certificate because of low consumption should see the change as a methodological tightening – not a defect in the heating system.

New allowances and floor areas

Besides data volume and normalisation, the draft shifts detail rules in Section 82 (compare current version; draft with changed allowances) that often go unnoticed when hot water or floor areas are incomplete:

Fuels in the draft are expressly to be assessed using gross calorific value – relevant for heating value vs gross calorific value in the consumption certificate.

On voluntary re-issue after entry into force, ratings may also shift through modernised primary energy factors and balance norms – a topic the GModG fact check covers for efficiency classes A+ to H.

Heating Costs Ordinance and metering

Monthly values do not appear by themselves. For many rented buildings, the draft’s 24-month duty is closely tied to the Heating Costs Ordinance (HeizkostenV):

• Since 1 December 2021, newly installed meters must be remotely readable (Section 5(2) HeizkostenV).
• Existing legacy devices in subject buildings are to be retrofitted by 31 December 2026 (Section 5(3) HeizkostenV).
• With remote-read technology, monthly consumption information for tenants is envisaged (Section 6a HeizkostenV).

Exemptions from HeizkostenV duties include detached homes, buildings with decentral heating (e.g. per-floor boilers) and two-family homes where the landlord occupies one unit (HeizkostenV Section 2 – check individual cases).

Timeline for rented multi-family buildings with central heating:

1. Retrofit remotely readable metering by end 2026
2. Then build a continuous monthly series over 24 months
3. Earliest end of 2028 realistic data basis for a consumption certificate under the draft

In owner-occupied detached homes, HeizkostenV linkage is often still missing longer. Without own metering or smart-home logging there is no monthly building data history – exactly what the draft will require.

Anyone who waits for retrofit until 2026 may miss the window in which a consumption certificate can still be issued under today’s data model.

Order a consumption certificate now – what pays off

By “order” we mean issue now – while Section 82 GEG still requires data many owners already hold. Waiting risks more effort and loss of the consumption option: through legal tightening, missing monthly data or a later act with different rules.

Legal classification

A consumption certificate issued under today’s rules is generally valid for ten years under Section 79(3) GEG. Certificates issued before entry into force of the new energy certificate provisions (Article 2 of the draft) remain usable for duties such as property advertisements – with transitional rules in the draft (Section 112, Section 87 GEG in the future version). That secures the consumption certificate type and today’s procedure (three periods, 2021 announcement), whether sale is in two or eight years.

A permanently favourable efficiency class is not secured. After refurbishment, heating replacement or voluntary re-issue, a new certificate may show different values.

Two risks in practice

Effective end of the consumption option: The draft does not abolish the consumption certificate for homes. Without 24 monthly values, after entry into force it is practically often no longer issuable in many stocks – especially detached homes without HeizkostenV duty and multi-family buildings only after metering retrofit from 2027/2028.

Political residual risk: For non-residential buildings the consumption certificate already ceases on re-issue. For homes the draft announces adaptation of Annex 10 GEG; the reference draft speaks of a fundamental overhaul of energy certificate law. Whether the residential consumption certificate survives long term is open. A valid certificate issued today reduces that uncertainty.

Background: GModG and the quiet announcement of a major energy certificate reform.

Consumption certificate in advance: keeping options open

For owners with a suitable data position, the advice is often not to re-issue every certificate hastily but a consumption certificate in advance: issue now although sale or letting is not imminent.

What “in advance” means:

• Use of today’s Section 82 data basis (three billing periods) while it is still available
• A valid consumption certificate with typically ten years’ validity
• On future sale, letting, lease renewal or listing, an immediately available document – without rebuilding monthly data (see also energy certificate duties)
• Keeping the choice between consumption and demand certificate; anyone who only knows the demand path may after reform be left with a single, often less favourable route

Especially sensible when:

• Detached or small multi-family home with complete heating cost statements but no prospect of monthly building data
• Sale or inheritance likely in the coming years, timing still open
• reform outlook unclear and you do not want consumption displaced by metering and GModG
• historical consumption still feeds favourably into the certificate under today’s methodology

Less sensible when:

• the data position already fails today (fewer than three periods, gaps, heavy vacancy without adjustment)
• short-term refurbishment or heating replacement is due – then issue targeted new certificates, not advance issue with outdated plant
• a current, valid consumption certificate already exists

“In advance” does not mean certifying every building by default. First check whether consumption is the better option than demand today – and if so, use the remaining window.

Energyausweis Smart™: which certificate type delivers the better class?

Whether the consumption certificate or the demand certificate delivers the more favourable efficiency class under today’s GEG cannot be answered from building type alone. Economical use can improve the consumption certificate; an unrenovated envelope can depress the demand certificate – and vice versa. Only calculation under the respective procedures shows which rating is better for your property.

With Energyausweis Smart™, energy consultants at energyausweis.de calculate both variants and issue the certificate that delivers the better result for you – without deciding in advance whether consumption or demand is the right choice. Especially before advance issue or the GModG transition, this comparison pays off: ordering only one type without comparing the other risks a worse class although data for both paths may still be available.

Background and examples: Energyausweis Smart™: how to increase your property’s value.

Decision guide

Advance scenario: A rented terraced house; sale possible in three to five years but uncertain. Three heating cost statements are available; monthly values will hardly be available after 2028. A consumption certificate now is a one-off cost, valid up to ten years, and avoids having only demand certificate and balance documents later.

Too late scenario: Wait until the act is passed. In 2027 monthly data are missing, the draft applies – the energy consultant issues only a demand certificate. The efficiency class is worse than expected; the sale is delayed.

Whether consumption or demand delivers the more suitable result depends on the building – comparing both under current GEG (see above) pays off especially before the transition. The comparison of both certificate types shows how strongly certificate type shapes the rating.

FAQ

Will the consumption certificate for homes be abolished?

Not legally: for purely residential buildings Section 82 remains in the GModG draft, but sharply tightened. After entry into force it may no longer be issuable for many homes without 24 monthly values. A later fundamental reform is announced politically. For non-residential buildings the consumption certificate already ceases on re-issue; the demand certificate under Section 81 remains.

Is a consumption certificate in advance worth it?

Yes, if at least three billing periods for the whole building are available today (Section 82(4) GEG) and the consumption certificate delivers a more favourable or more suitable result than the demand certificate. That secures up to ten years’ validity under today’s logic (Section 79(3) GEG) – regardless of monthly-data duties and reform plans. No, if the data position is already patchy or refurbishment and re-issue are due soon anyway.

Do I have to replace my old consumption certificate because of GModG?

No. Valid certificates keep their period of validity (Section 79(3) GEG; generally ten years) – unlike the fear that “all certificates expire from 2026” (see Will energy certificates become invalid from 2026?). Only in mandatory cases – sale, letting, renewal without a valid certificate – is a current one required, not because of the reform as such.

Are my heating cost statements still enough?

Today, generally yes if at least three billing periods within 36 months are available (Section 82(4) GEG). After entry into force of the draft only if 24 monthly values split by carrier can be derived from them (Section 82(1) and (4) GModG draft).

What if I can no longer get a consumption certificate after the reform?

Then the demand certificate (balance under Section 81 GEG) remains – legally equivalent, with a different data basis (envelope, plant). For mixed-use buildings this will apply more strongly in future anyway.

Conclusion

The consumption certificate for homes is not slated for abolition in the cabinet draft – but the data requirement becomes so demanding that it effectively disappears for many stocks. Anyone who still manages with three billing periods today is using a closing window, not a permanent state.

Check whether a consumption certificate still makes sense for your property and, with a suitable data position, issue in advance while Section 82 GEG applies. That keeps options for sale, letting and inheritance – even if monthly data, normalisation under DIN Table 5 or a later act further narrow the consumption route.

Three guiding questions:

1. Do your statements suffice for a consumption certificate today – or only for demand?
2. Are you planning sale, letting or inheritance in the next ten years without rebuilding data?
3. Is losing the consumption option acceptable once the draft applies or metering is missing?

Those with the data gain leeway with a consumption certificate in advance; those who wait often choose later only between demand certificate and higher effort.

The GModG fact check covers the full cabinet draft.

Whether a consumption certificate is still issuable for your building – for the next mandatory case or in advance – can be checked under current law at energyausweis.de before the 24-month duty and new methodology apply.