GModG for Property Managers: Annual Consumption Data, Modernisation Recommendations and HOA Resolutions

Joost Jansky

Energieberater, Blogger

Note: Section references relate to the promulgated GModG (BGBl. 2026 I No. 226). For the overview of the certificate reform from 2027, see the hub article. If you operate a property-management platform rather than managing properties yourself, the same question from a SaaS perspective is in the sister article GModG for property-management platforms.

What changes for you as a property manager with the GModG

Three new or tightened duties land from 1 January 2027 (Article 2) directly in the day-to-day business of property management — whether you offer rental management, HOA management or both — and are backed by fines of up to 10,000 EUR per offence under § 108 GModG:

The point: from 2027 the energy certificate is no longer just a document delegated to an issuer once every ten years. It becomes a data set that emerges directly from the heating-cost-ordinance routine — and a basis for resolutions in the owners' meeting. Both end up on the management's desk; the question is not whether, but how structured.

HeizkostenV and GModG: why the remote-readability deadline is the door opener

The good news first: anyone who has implemented the HeizkostenV duties cleanly will have most of the § 82 data foundation as a by-product from 1 January 2027.

Three deadlines mesh:

• By 31 December 2026 existing equipment that is not remotely readable must be retrofitted or replaced under § 5 (3) HeizkostenV. A special deadline up to 31 December 2031 applies only to equipment that is already remotely readable but not interoperable (§ 5 (4)).
• Since 1 January 2022 § 6a HeizkostenV has required at least monthly consumption information to users. Anyone running this routine since 2022 has reliable raw data — from which the annual periods that § 82 will require from 2027 can be aggregated.
• § 12 HeizkostenV shows the immediate economic lever: where remote-readability or information duties are breached, users may reduce their share of the heating costs by 3 percent per breach, cumulating up to 6 percent. This does not hit the property manager personally but the homeowners' association — and in the meeting this argument for migrating the meters explains itself.

In other words: anyone who reports in line with § 6a today and has the deadline-driven meter migration in their plan is also building the § 82 data foundation as a side effect. Portfolios with retrofit backlogs will face two regimes from 2027 — HeizkostenV § 12 on one side, GModG § 82 on the other.

A concrete example: a homeowners' association of 24 dwellings, central natural-gas heating, remotely readable heat meters since 2022, exclusively residential use. The portal of the heating-cost service provider delivers monthly consumption data per dwelling — heating and domestic hot water separately. If a consumption-based certificate is commissioned from 1 January 2027 for the next leasing listing, two annual settlement periods suffice (e.g. calendar years 2025 and 2026), per energy carrier — provided the most recent period is no more than 18 months old. A CSV export, one row per year or settlement period and energy carrier — and § 82 is satisfied. The effort per order drops from several hours of data preparation to a few minutes.

The data question: where do the annual consumption data come from?

From 1 January 2027, § 82 requires final-energy consumption annually, differentiated by energy carrier, over two years. The most recent settlement period must not be more than 18 months old. The consumption-based certificate is only allowed for buildings used exclusively for residential purposes — narrower than the “predominantly residential” definition of a residential building. Even a small commercial share usually leads to a demand-based certificate under § 81.

Three sources are provided: heating-cost-ordinance settlements for the whole building, other suitable consumption data (such as energy-supplier bills or consumption measurements), and combinations of the two.

In practice most managements work with one of the four large heating-cost service providers: ista, Techem, Brunata-Minol or KALO. The depth of the data export your provider delivers today depends heavily on the contract package. The standard is a manager portal with a CSV or Excel export; openly documented REST APIs are the exception. How that plays out in five typical configurations from existing portfolios:

Important note on the flat rates: § 82 only allows the +16 kWh/(m²·a) for domestic hot water and +6 kWh/(m²·a) for cooling if the corresponding consumption is not known. They are a fallback for missing data, not a standard surcharge. Where meters are present, their values are to be used — even if the flat rate would be more favourable on paper.

What owners can do in the same situation is described in the sister article Consumption-based certificate: preparing for the new data requirements; the article on the free choice between demand-based and consumption-based certificate clarifies when the consumption-based certificate is the simpler route for an HOA; for multi-family buildings with cost examples and an HOA perspective see Energy Certificate for Multi-Family Buildings.

HOA resolution & manager liability

The question that comes up in almost every property-manager briefing: do I need a resolution from the owners' meeting before every energy-certificate order?

The prevailing view in the commentary literature classifies ordering an energy certificate as proper administration within the meaning of § 19 (2) WEG. Under § 27 (1) WEG the manager may take measures of proper administration of subordinate importance, provided they do not give rise to substantial obligations — or measures necessary to meet a deadline or to avert a disadvantage. There is no Federal Court (BGH) line specifically for ordering an energy certificate without a resolution. Practical advice: have the next owners' meeting pass a blanket authorisation — phrased for example as "authorisation of the management to commission due energy certificates directly, provided the order amount in each individual case does not exceed X euros". This is anti-challenge protection against § 44 WEG actions and resolves the timing conflict between the leasing trigger and the meeting frequency.

The question goes further when the energy certificate becomes the basis of a refurbishment resolution. A § 84 recommendation block with concrete figures — remaining lifetime of the heating system in years, low-temperature compatibility yes/no, estimated kWh and CO₂ savings — reads like an advisory result and can act exactly that way in a resolution draft for a heat-pump investment. If such values enter the resolution text, managers carry due-diligence obligations regarding the source citation. Three notes are worth including in every draft:

• Source designation (energy certificate dated DD.MM.YYYY, issuer, DIBt registration number).
• Note on the estimate character of the § 84 recommendations — they do not replace an individual refurbishment roadmap (iSFP) or detailed building-physics calculations.
• Before far-reaching investments, commission an energy advisor to verify the specific measure.

Anyone who implements this significantly narrows the challenge corridor under § 44 WEG. The one-month deadline from the date of the resolution (§ 45 WEG) remains unchanged.

In the internal relationship, § 280 BGB applies in the case of breach of duty under the management contract (§ 675 BGB). There is no published Federal Court (BGH) or Higher Regional Court (OLG) decision specifically on the manager's failure to order an energy certificate. For the magazine-level state of play that means: this is an organisational duty, not a specifically adjudicated damages threat. Anyone who initiates orders on time, documents the timing of disclosure and handover, and feeds the data from the issuer back into the master file in full has covered the duty-of-care corridor.

What technically fills this duty-of-care corridor from 2027 is decided at § 84 — where the recommendation block of a certificate becomes a list of figures that flows directly into the next resolution draft.

Modernisation recommendations § 84: a mini roadmap instead of a platitude

§ 84 (1) GModG transposes Article 19 (7) to (9) of the EU buildings directive (EU) 2024/1275 and turns today's recommendation block into a quantified mini roadmap. Specifically, the issuer must provide the following in the energy certificate:

• An estimate of the energy savings and of the reduction in operational greenhouse-gas emissions per measure.
• An assessment of whether the heating, ventilation, air-conditioning and domestic-hot-water systems can be adjusted to operate at more efficient temperature settings — the heat-pump compatibility or low-temperature compatibility.
• An assessment of the remaining lifetime of a heating or air-conditioning system, and optionally possible alternatives for replacement, taking local and system-related conditions into account.

The duty to issue recommendations only falls away if the technical assessment shows that no meaningful measures are possible — or if the overall energy-performance class corresponds to class A. For most managed portfolios this is a theoretical exception: the bulk of residential buildings sits between classes B and H.

Reading note: the wording of § 84 (1) GModG explicitly excludes only "class A", not "class A+ or A". Until an editorial clarification, we go by the strict wording.

What does this mean in everyday property management? Until now the recommendation block has landed as a free-text section in the PDF and disappeared into the master file. From 2027 it is the data foundation from which HOA refurbishment plans grow. Anyone who only receives the certificate as a flat PDF image will have to re-type the same values into the meeting draft manually — error-prone and without an audit trail.

An ordering solution that returns the recommendations as structured data — for example, per measure:

• description — e.g. "replace gas condensing boiler with air-to-water heat pump"
• kwh_savings_per_year — e.g. 18,000
• ghg_savings_kg_co2 — e.g. 4,200
• remaining_heating_lifetime_years — e.g. 3
• low_temperature_compatible (boolean) — e.g. true

— turns the certificate into a reusable data source for resolution drafts, funding advice (BEG-EM, iSFP) and reporting to the advisory board and owners. The technical lever from the platform perspective is covered in the sister article GModG for property-management platforms.

A second mandatory field under § 85 (1) no. 27 GModG rounds out the picture: where a heat-distribution system is in place, a yes/no statement on low-temperature compatibility is mandatory in the certificate. For the management this means: even before the next owners' meeting, you can already filter from the existing certificates which portfolios still have a distribution system that is not heat-pump-ready — and start preparing measures there earlier.

How do you plan today? Four-point checklist

Realistically the window until 1 January 2027 is manageable. Anyone who only starts preparing on the cut-off date will collide with the running day-to-day business. The earlier the four points below are set up, the calmer the transition phase can be steered.

Outsourcing the ordering: the Energyausweis API for property managers

Anyone who has structured the four points above cleanly will end up facing an in-house-or-issuing-partner decision: do you build the ordering and data routes into your own management software — or do you connect a specialised issuer through an interface?

Three arguments speak for the API variant from a property-manager perspective:

• Bulk ordering instead of single-case workflow. Owner changes, lease renewals and HOA refurbishment resolutions arrive in waves. An ordering interface that triggers several jobs at once via CSV or list import shifts the effort per order from 30 minutes to a few seconds.
• JSON return into resolution drafts. Receiving the § 84 recommendations as structured fields — not just as a PDF image — is the precondition for turning the energy certificate into a resolution draft without re-entering the data. Refurbishment-roadmap data, federal funding applications (BEG-EM) and reports to the advisory board can all be fed from the same fields.
• Audit trail for the management file. DIBt registration number, issue date, expiry date, PDF hash and data origin documented for every certificate evidence the duty of care under § 280 BGB in the internal relationship and support the disclosure and handover offences under § 108 (1) no. 18, 19 GModG.

Three quality criteria belong in every issuer selection: review of the data set and on-site inspection by certified energy advisors under DIN/TS 18599:2025-10, DIBt registration number on every certificate, and traceable data origin in the audit trail. If you operate a platform and want to integrate the interface yourself, you will find the technical view in Energyausweis API for online portals and in the platform sister article already mentioned, GModG for property-management platforms.

Managements without their own software platform pull the lever via an integrated issuer. The ordering route stays inside the management contract, the audit trail in your own system; only the issuance itself is outsourced. That is also the part a management is not allowed to perform itself — the issuing authorisation under § 88 GModG is tied to the qualified energy advisor as a person, not to software licences or management functions.

FAQ for property managers

Do I need a resolution from the owners' meeting to commission an energy certificate as the property manager?

The prevailing view is that ordering the certificate is proper administration within the meaning of § 19 (2) WEG and is covered by the manager's right of order under § 27 WEG — the highest courts have not yet ruled on this. Practical advice: have the next owners' meeting grant a blanket authorisation with a per-case order ceiling. This excludes § 44 WEG challenge risks and resolves the timing conflict between the leasing trigger and the meeting frequency.

Where do the annual consumption data over two years per energy carrier come from?

From 1 January 2027, § 82 requires annual, energy-carrier-differentiated consumption data over two years; the most recent settlement period must not be more than 18 months old. The consumption-based certificate is only allowed for buildings used exclusively for residential purposes. Sources are heating-cost-ordinance settlements for the whole building, other suitable consumption data (energy suppliers or consumption measurements) and combinations. In practice the data come from the manager portals of ista, Techem, Brunata-Minol or KALO — often as annual aggregates or aggregated from monthly § 6a data. Anyone who has been delivering monthly consumption information per § 6a HeizkostenV cleanly since 2022 has the raw data as a by-product.

What happens if a modernisation recommendation in the certificate later turns out to be wrong?

The § 84 recommendations are explicitly framed as estimates, not as an individual refurbishment roadmap (iSFP). Anyone who copies them into a resolution draft without scrutiny runs into two risks: § 44 WEG challenge of the resolution because of an inadequate evidentiary basis, and in the internal relationship a breach of duty under § 280 BGB. There is no published Federal Court (BGH) or Higher Regional Court (OLG) ruling specifically on faulty § 84 recommendations yet. Practice: source citation with the DIBt registration number in every draft, a note on the estimate character, and consult an energy advisor before far-reaching investments.

Does a valid older certificate continue to be sufficient after the GModG enters into force?

Yes. § 80 (3) sentence 1 GModG only mentions the issuing duty "if a valid energy certificate for the building does not already exist". Existing certificates with remaining validity (typically ten years from issuance) remain usable for the rest of their term. For the full overview of the certificate reform from 2027, see the hub article.

How does the heating-cost-ordinance deadline of 31 December 2026 affect the energy certificate?

The heating-cost-ordinance deadline concerns the remote readability of meters — the technical foundation for reliable consumption data. Anyone who fulfils the § 5 (3) duty by the end of 2026 will have continuous consumption data from then on. Portfolios that miss the deadline simultaneously risk a § 12 HeizkostenV reduction right of the users (3 percent per breach, cumulating up to 6 percent) on top of the GModG pressure. The two regimes reinforce each other.

What can I do for small homeowners associations (under 10 units) without remote-readable meters?

The heating-cost-ordinance duty for remote readability applies regardless of size. For small associations the cost per unit is higher — but meetings are shorter and resolutions faster. Realistic procedure: (1) blanket authorisation together with a resolution to migrate the meters in the current owners' meeting, (2) bundling the procurement with the next heating-cost settlement. The § 82 data foundation arises automatically in the next settlement period once the devices are remotely readable.

Conclusion: three steps until 1 January 2027

Three preparatory levers can be started independently of one another — and laid out in parallel:

• Pass a blanket authorisation at the next owners' meeting, with a clear per-case ceiling. This resolves the timing conflict between the leasing trigger and the meeting frequency, and excludes § 44 WEG challenge risks.
• Establish a portfolio scan and data-export routine: three fields per property (remote-readable meters, valid certificate, expiry date), combined with the regular CSV/Excel export of annual periods from the heating-cost-ordinance portal. This makes the § 82 data foundation tangible on 1 January 2027, not on the day of the first order.
• Clarify an API connection to an issuer with structured data return — either via your own management software or directly, depending on the maturity of your IT landscape.

Anyone who has these levers in place before 1 January 2027 translates § 80, § 82, § 84 and § 108 GModG into a workflow that turns the certificate into a data source — for the next owners' meeting, for the HOA refurbishment roadmap and for funding advice. Article 2 (EPBD energy certificates) applies from 1 January 2027; Article 1 (renaming and heating reform) has been in force since 29 July 2026.

How to take it further:

• API documentation and try-it. Read the OpenAPI 3.1.2 specification — Bearer authentication, free partner usage, bulk ordering via list import.
• Tailored package for property managers. Talk to us about bulk ordering, a connection to your management software and white-label.
• Hub on the certificate reform. Read the full state of play from 2027 in the hub article.