Solar Obligation for New Builds 2026: All 16 Federal States at a Glance

Whether your new prefabricated house needs a photovoltaic system depends in 2026 on the federal state (Bundesland) — there is no nationwide solar obligation for new residential builds. This guide lists all 16 federal states, explains the different obligations and shows what this means for your new build in concrete terms. You can first use our calculator to calculate prefabricated house costs and assess your budget realistically.

How is the solar obligation regulated in the 16 federal states?

What do a "should" rule and a "PV-ready obligation" mean?

Not every rule is a hard requirement. Bavaria's "should" rule (Soll-Regelung) phrases PV installation as an expectation but leaves room for discretion — the builder "should", but does not have to in every case. With the PV-ready obligation, Rhineland-Palatinate at least requires the roof to be prepared structurally and electrically so that a system can later be retrofitted without a major rebuild. In the six obligation states, on the other hand, the system must be installed directly with the new build — usually referring to a minimum share of the suitable roof area.

In practice this means: even without a hard obligation, it is almost always worth planning the roof to be at least PV-ready. You can read details on the technology in the guide photovoltaics in the prefabricated house and in combination with storage under PV, storage & wallbox.

Is photovoltaics worthwhile even without an obligation?

Anyone combining PV with a heat pump and storage can cover a large part of their electricity needs themselves — right up to an energy self-sufficient house. An overview of system types and funding is also provided by the page solar system as well as the guide GEG for prefabricated houses 2026. Anyone wanting to deepen the basics will find them in the prefabricated house overview.

Which exceptions and transitional rules are there?

No solar obligation applies without exception. As a rule, the state regulations provide for exceptions when installation is technically impossible or economically unreasonable — for example in the case of permanent shading from neighbouring buildings or trees, an unfavourable roof orientation or heritage protection. There may also be relief for very small roof areas or certain types of use. Instead of a classic rooftop system, some states also allow alternative compliance routes, for example solar thermal or a system on an outbuilding.

Because the details vary by federal state and sometimes by municipality, and because the regulations change regularly, clarifying matters early with the building supervisory authority is crucial. It is best to plan the PV system in from the outset — this is usually cheaper than a later retrofit and avoids conflicts with the permit.

How do you sensibly plan the PV system in?

For an economical PV concept, more than mere compliance counts. What matters is a roof area that is as large and unshaded as possible with a south, east or west orientation, a system size matched to the expected consumption, and the question of whether a battery storage system makes sense. Anyone additionally running a heat pump and a wallbox for an electric car benefits especially from a larger system, because self-consumption rises.

Consider the electrical planning early: conduits, meter cabinet and connection points are much easier to provide for during the shell construction than later. On request, a good prefabricated house provider plans PV, storage and charging infrastructure in from the start. Background on technology and yield is provided by the page solar system. How the obligation can be embedded into a well thought-out, CO₂-neutral overall concept is described in the guide on the climate-neutral villa.