Order a consumption certificate now – before the consumption-data rules change

Joost Jansky

Energieberater, Blogger

In brief: GModG and the consumption certificate from 2027

The consumption-based energy certificate remains available for buildings with exclusive residential use — it is not abolished. What changes are the building scope, the data basis and parts of the calculation method. Today three billing periods often suffice; from 2027 Section 82 requires annual values over two years, split by energy carrier — without a statutory monthly matrix.

Four points frame the debate:

1. Exclusive residential use only: From 2027 Section 82 applies only to buildings used exclusively for residential purposes. “Residential building” (= predominantly residential) is not enough.
2. Non-residential buildings: On sale, letting or renewal, non-residential buildings keep the certificate based on an energy balance (Section 81) — the consumption certificate ends there on re-issue.
3. Residential buildings – certificate choice (Section 80 (3)): Today Section 80 (3) bars many older small residential buildings (fewer than five units, application before 1 Nov 1977) without WSchV-1977 proof from the consumption route. From 2027 that link disappears; consumption stays tied to Section 82 and pure residential use. Detail: Choice and the WSchV77 hurdle.
4. Timing: Article 2 applies on 1 January 2027 — not “six months after promulgation” as in the cabinet draft.

The hub GModG proclaimed situates the full package.

Existing certificates are not voided wholesale. The key question is whether you want to issue under the interim rules before the format change — and whether from 2027 consumption (pure residential use + annual data) or demand is the better path.

From three billing periods to annual two-year data

Today: billing periods

Under Section 82 (4) GEG you need consumption data from at least three consecutive billing periods within a continuous span of typically 36 months. The most recent period may be no more than 18 months ago. In practice many owners rely on annual heating-cost or supplier statements.

Practice example (today): Detached house with gas heating, three annual bills 2023–2025 — under the interim rules that often supports a consumption certificate.

From 2027: annual over two years — not 24 monthly values

Final Section 82 requires annual, energy-carrier-differentiated consumption data over two years. The most recent period stays at most 18 months (the draft wanted 15 — that did not become law). There is no duty to supply 24 monthly values.

Consequence: Owners with solid annual bills across two heating seasons and exclusive residential use are often closer to the consumption route than the earlier draft thesis suggested. Without carrier splits, recency or pure residential use, the demand certificate remains.

Checklist: is the data available?

• Is the building used exclusively for residential purposes (no commercial share)?
• Are consumption values available for the whole building (not only one flat)?
• Can values be assigned by energy carrier (gas, oil, district heat, electricity)?
• Do the data cover two annual periods (today: three periods in ~36 months)?
• Is the most recent period still within 18 months?

With mixed use or missing carrier splits, the consumption certificate from 2027 is often not the path — then demand remains. A missing monthly series alone is no longer an exclusion ground under the draft logic.

Weather adjustment and normalisation

Annual consumption values are the first prerequisite. Section 82 additionally requires weather adjustment and normalisation to the standard occupancy conditions for residential buildings under DIN/TS 18599-10:2025-10 Table 5 — with due regard to user behaviour including longer vacancies.

Today Section 82 (5) GEG and the notice on consumption values (29 March 2021) focus mainly on climate factors and vacancy adjustment. From 2027 the logic ties more closely to the standards family that describes normalised use for demand certificates.

The official calculation method in the Federal Gazette will close the details. For now the 2021 procedure still applies — one reason issuing before the cut-off can lock today’s method for up to ten years.

What “standard occupancy conditions” mean for you

Normalisation refers to Table 5 of DIN/TS 18599-10:2025-10 — guide values for typical residential use (room temperatures, operating hours, occupancy, ventilation, domestic hot water).

With frugal heating, the reported consumption after normalisation can sit higher than everyday use. Longer vacancy was already limitedly adjustable. A “good” consumption result reflects typical residential use more strongly — not individual thrift alone.

Practice example: A sale-ready terraced house is heated to 18 °C. Measured gas use is low; after normalisation the rating can look worse than buyers expect. Anyone who preferred consumption because of low readings should treat the change as a method shift — not a heating-system fault.

New flat rates and floor areas

Besides data and normalisation, detail rules shift the rating — often unnoticed when domestic hot water or floor-area figures are incomplete:

Fuels are to be considered with the gross calorific value — relevant for net vs gross calorific value in the consumption certificate.

On voluntary re-issue from 2027, ratings can also move with modernised factors and the new certificate format (including A+–H) — see the hub GModG proclaimed.

Heating Costs Ordinance and metering

The Heating Costs Ordinance (HKVO) remains relevant for let buildings with central heating — but no longer as the driver of a Section 82 monthly matrix:

• Since 1 December 2021, newly installed meters must be remotely readable (Section 5 (2) HeizkostenV).
• Existing legacy devices in obligated buildings should be retrofitted by 31 December 2026 (Section 5 (3) HeizkostenV).
• Where remotely readable, monthly consumption information to tenants is provided (Section 6a HeizkostenV).

Exceptions include detached houses, decentral heating and certain two-family houses (HKVO Section 2).

What changes in the earlier thesis: The story “retrofit 2026 → collect 24 months → consumption certificate only from end-2028” was tied to the draft monthly rule. That rule does not apply. For Section 82 from 2027, annual data over two years count. Remote-readable kit and monthly tenant infos remain useful for transparency and billing — they are not a legal reason to postpone the consumption certificate until end-2028.

In owner-occupied detached homes, HKVO data are often missing anyway: annual bills and your own records decide.

Order a consumption certificate now – when it still pays off

“Order” means issuing now — while the interim rules apply and many owners already hold three billing periods. The former pressure “before 24 months of monthly data become mandatory” falls away. Other reasons remain.

Legal framing

A consumption certificate issued under today’s rules is generally valid for ten years under Section 79 (3) GEG. Certificates issued before Article 2 takes effect remain usable for duties such as property adverts — with the transitional rules (including Section 112). That secures the consumption certificate type and today’s process logic, whether the sale is two or eight years away.

A permanently favourable efficiency class is not locked in. After renovation, heating replacement or voluntary re-issue, a new certificate can show different ratings and, from 2027, the new format.

Why ordering before 2027 can still make sense

1. Format change: Re-issues from 2027 follow the Article 2 certificate (including A+–H and digital output).
2. Exclusive residential use: Mixed use loses the consumption route from 2027 anyway.
3. Listed buildings: The previous certificate-duty exception ends from 2027.
4. Methodology: Normalisation and flat rates can shift ratings — a certificate issued today holds today’s logic.
5. Choice for small older homes: If you are still blocked by the WSchV77 hurdle, see Choice and WSchV77 — from 2027 consumption opens for pure residential use.

Not the reason: a statutory monthly-data duty. Final law has none.

Consumption certificate in advance: keep options open

For owners with fitting data, the answer is often not to re-issue every certificate at once, but a consumption certificate in advance: issue now, even if sale or letting is not imminent.

What “in advance” means:

• Use today’s Section 82 data basis (three billing periods) while it is available
• A valid consumption certificate with typically ten years’ term
• For a later sale, lease, lease renewal or advert, an immediately available document
• Locking today’s method and class across the format change

Especially useful when:

• Detached or small multi-family home with complete annual bills and pure residential use
• Sale or inheritance in the coming years is likely, timing still open
• You want to keep today’s result (without new normalisation/format) for adverts

Less useful when:

• data already fall short (fewer than three periods, gaps)
• mixed use applies — demand from 2027 anyway; issue consumption now only if still allowed and advantageous
• near-term renovation or heating replacement is planned
• a current, valid consumption certificate already exists

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

Whether the consumption certificate or the demand certificate delivers the more favourable efficiency class cannot be answered from building type alone. With Energyausweis Smart™ auditors calculate both variants and issue the more advantageous certificate.

Background: Energyausweis Smart™.

Decision aid

Scenario in advance: Let terraced house, purely residential, sale possible in three to five years. Three heating-cost statements are on file. A consumption certificate now costs once, lasts up to ten years and avoids clarifying the format change and new method mid-sale.

Scenario wait: No occasion, data and pure residential use clear — then keep annual data and reassess from 2027. The former “end-2028 monthly data” pressure falls away.

FAQ

Will 24 monthly values become mandatory for the consumption certificate?

No. The draft rule did not become law. From 1 January 2027: annual data over two years, at most 18 months recency, only for exclusive residential use.

Will the consumption certificate for homes be abolished?

No. For purely residential buildings Section 82 remains. Mixed use and non-residential buildings on transaction → usually a demand certificate under Section 81.

Is a consumption certificate in advance still worth it?

Yes, if at least three billing periods are available today, use is purely residential and the consumption certificate delivers the better fit. You secure up to ten years under today’s logic (Section 79 (3) GEG) — because of format, listed buildings and method, not because of a monthly-data duty.

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

No. Valid certificates keep their term. Only mandatory cases without a valid certificate require a current one — not the reform itself (see also Do energy certificates become invalid from 2026?).

Are my heating cost statements still enough?

Until 31 Dec 2026, generally yes if three periods within ~36 months are available. From 2027: annual data over two years, by energy carrier, ≤ 18 months, only for exclusive residential use — without a duty to supply 24 monthly values.

Conclusion

1. The draft thesis “24 months of monthly data become mandatory” is outdated — final law uses an annual two-year rule.
2. The consumption certificate remains for exclusive residential use; mixed use → demand.
3. Ordering before 2027 can still pay off: format, listed buildings, method, ten-year certainty.
4. Collect annual consumption by energy carrier — that helps under the interim rules and from 2027.

Check whether a consumption certificate still fits your property, and issue it in advance when the data fit — or wait deliberately, without the former monthly-data pressure.

Full framing: GModG proclaimed — new energy certificate from 2027.

Whether a consumption certificate can be issued for your building — for the next mandatory case or in advance — can be checked under current law on energyausweis.de.