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Glossary · Energy industry & energy transition

Mandatory Connection and Use Requirement (Anschluss- und Benutzungszwang)

Mandatory connection and use heat network district heating municipality statutes heat planning

Mandatory Connection and Use Requirement (Anschluss- und Benutzungszwang)

The mandatory connection and use requirement (Anschluss- und Benutzungszwang) is an obligation under public law to connect a property to a specific public facility and to use it. In the energy sector, it relates above all to heat networks and district heating. The connection requirement concerns the technical link-up; the use requirement obliges the owner to purchase heat to the prescribed extent. Who is obliged, which buildings are covered and when the obligation begins follow from the applicable statutory basis and the local by-law (Satzung).

The following assessment concerns Germany, as of 11 November 2026. There is no nationwide uniform connection requirement for all buildings. What matters is the respective state law (Landesrecht) and the specific municipal regulation. A technical connection option or a pipe in front of the house does not, in itself, create an obligation to use the network.

Connection and use are different obligations

By way of illustration: a connected house could technically cover part of its heat demand from the network and another part from solar thermal energy. Whether this is legally permitted must be examined separately. The technical connection therefore does not answer the question of whether additional heat generators may be operated. Likewise, a use requirement should not be confused with a blanket obligation always to consume the same amount of heat regardless of actual demand.

For a comprehensible regulation, space heating, hot water and, where applicable, commercial process heat should be considered separately. The time of connection, the operational readiness of the network and the transition from an existing heating system also deserve clear rules. A regulation would be particularly prone to conflict if owners were obliged to give up their previous supply while the start of a reliable replacement supply remained unclear.

Legal bases and public purposes

Municipal authority requires a basis in state law. In addition, § 109 of the Gebäudemodernisierungsgesetz (Building Modernisation Act), formerly the Gebäudeenergiegesetz (Building Energy Act), permits such authorisations to be used also for climate and resource protection. The provision covers public district heating and district cooling networks. It does not itself order the connection of individual properties and does not replace the examination of the requirements under state law.

One example is § 11 of the Gemeindeordnung of Baden-Württemberg (Municipal Code): where there is a public need, the municipality may adopt a by-law on local and district heating supply. Restrictions to parts of the municipal area or to certain groups are possible. Paragraph 3 also contains a special authorisation for existing buildings, excluding public buildings of the Federation. There, exceptions must be provided for where the obligation is unreasonable for economic reasons or because of the existing energy quality of the building. This state-level example cannot be transferred unchanged to other federal states.

For the assessment, the public purpose and the operator's interest should be kept apart. Predictable revenues may facilitate the construction of a network; by themselves, however, they do not yet provide sufficient justification for a sovereign obligation. The questions to ask are: Which public problem is to be solved? How does precisely this supply concept contribute to it? And why should precisely this area be made subject to the obligation?

A public facility does not necessarily have to be operated by the municipal administration itself. The Federal Administrative Court (Bundesverwaltungsgericht) has in principle accepted private operators and supply relationships under private law. In the Schleswig-Holstein case decided, however, sufficient safeguards were lacking; the court emphasised effective municipal control and influence, as well as securing supply in the event of an operator's failure.

Heat planning does not yet mean a connection requirement

Heat planning and a binding connection obligation must be kept separate. Under § 23(4) of the Wärmeplanungsgesetz (Heat Planning Act), the heat plan has no external legal effect and does not create enforceable rights or obligations. Under § 27(1), the separate designation of areas under § 26 likewise creates neither an obligation to use a particular type of heat supply nor an obligation to build, expand or operate the corresponding infrastructure.

A coloured heat-network area on a planning map is therefore neither a connection order nor a supply guarantee. For an investment decision, it should additionally be clarified whether a specific expansion has been decided, who is financing it, when the network is expected to be available and what legal obligation actually exists.

Other instruments should also be kept conceptually separate: a subsidy provides a financial incentive; a technical building requirement concerns the design of an installation. A contractual connection commitment in a property purchase, in turn, is not a public-law by-law obligation. In the case of a contract clause, the contracting parties, scope, validity and consequences of a change of ownership would have to be examined separately. A development plan, a concession or a funding commitment should not be treated, without examination, as a substitute for the required authorisation.

Network economics and its limits

The economic consideration can be shown with a simplified example: if the same street pipe initially has to supply only a few houses, its costs are spread over fewer customers than in a street where most buildings are connected. A use requirement is intended to make not only connections but also ongoing sales more reliable. This is an explanation for the instrument, not yet proof of its legal permissibility or economic superiority.

A robust economic assessment should therefore examine more than the connection rate: expected heat sales, pipe lengths, losses, financing, generation and the development of demand over time. As a comparative calculation, a scenario with building renovations and declining consumption is also advisable. A network should not appear viable merely because a permanently unchanged high level of sales is assumed.

Proportionality, existing buildings and exceptions

A compelled obligation interferes with the freedom of decision of those affected and must be proportionate. The assessment requires more than a reference to a politically desired heat network. The organisational safeguarding of supply is also part of it.

Three questions lend themselves to a practical review: Does the obligation promote the stated purpose? Could less burdensome solutions be sufficiently effective? Are benefits and burdens in an appropriate relationship? Voluntary connection offers, subsidies and solutions staggered over time should be seriously examined in this context and not merely mentioned as a formality.

For existing buildings, the age and remaining useful life of the heating system, recent investments, necessary conversions and special uses should be documented. A functioning climate-friendly individual supply deserves different consideration than a heating modernisation that is due anyway. This does not, however, imply a blanket exemption for all heat pumps or all particularly energy-efficient buildings; exemption grounds and procedures must be examined on the basis of the applicable law.

Contract, prices and consumer protection

The by-law obligation and the supply conditions are different levels. The AVBFernwärmeV (Ordinance on General Conditions for the Supply of District Heating) generally applies to standardised district heating contracts under private law; industrial undertakings are excluded. Among other things, it contains publication rules for prices and price adjustment clauses. Supply relationships regulated under public law must be designed accordingly under § 35; municipal fees and charges law remains unaffected.

§ 3 AVBFernwärmeV contains rights to adjust the capacity and, under certain conditions, to terminate the contract where heat is replaced by renewable energy. However, an exemption from a by-law obligation existing alongside it should not be inferred without examination. Both legal relationships must be considered together.

For the cost comparison, an overall calculation is advisable: connection and building conversion, ongoing fixed and consumption-based charges, maintenance and later replacement investments. A comprehensible price structure is especially important where the obligation is mandatory. It should likewise be clarified in advance which body handles complaints and how price changes can be verified. A by-law is not a seal of quality for an inexpensive tariff.

Consequences for the electricity system and flexibility

For the energy assessment, the actual supply concept should be considered: for example, waste heat use, geothermal energy, combined heat and power or large-scale heat pumps. In the case of electric heat generation, thermal storage and operational flexibility must also be examined. What matters is not only the annual amount of energy, but also when electrical capacity is needed and what alternatives exist during cold hours.

A meaningful comparison therefore sets the same buildings and the same supply standard side by side: decentralised heating systems on the one hand, the specific heat network on the other. Without such a comparison, neither a relief nor an additional burden on the electricity grids should be asserted. Nor does the connection requirement itself prove a better climate balance.

The mandatory connection and use requirement is thus neither automatically a sign of poor district heating nor a substitute for good planning. For a reasoned assessment, the legal basis, public benefit, exceptions, costs, security of supply and technical concept must fit together. The decisive question is not only whether many buildings can be bound, but whether the specific obligation is objectively justified and designed in a way that is reasonable for those affected.

Sources

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Edited by eCMS on 11.11.2026 13:58

© 2026 Erik Schmidt. All rights reserved. Quotations with a link to the source are welcome.