Minimum size photovoltaic system for new construction

Hello.

For our planned house construction, I am wondering what the minimum size for photovoltaic systems is.

Is there a regulation on how much of the roof area must be covered or how many kWp must be installed?

The question here is explicitly not about economic viability but about legal requirements.

Are there also legal requirements regarding whether a storage system is needed?

The house will be heated with 100% sustainable district heating.

As an electrician, I will definitely install a photovoltaic system, but the question is whether I have to consider anything, or if I can do it however I want, and especially when I want to, or can/want to afford it.

Thank you very much
Best regards Ralf

There is (unfortunately) not yet a nationwide obligation to install photovoltaic systems on new buildings. However, there may be such regulations regionally.

For our planned house construction, I am wondering what the minimum size for photovoltaics is.

In BW, it is 60% of the suitable roof area. You can find the exact calculation in the law or in the guide to the photovoltaic obligation.

No legal requirements according to KfW or QNG (at most indirectly, to achieve appropriate values).

State requirements in BW/B/Hamburg; Bremen/Nds/NRW in discussions or with requirements starting in 2025.

Check with your state ;-)

Hello.

I have now also found something, at first there were lots of search results about what size makes sense etc.

As I see it, the southern roof surfaces (deviating by 60 degrees to the east or west) are suitable surfaces, these must be covered with 60% of the area.

Alternatively 0.06 kWp per m² of built-up land area

"The photovoltaic requirement is considered fulfilled if the photovoltaic system has an installed minimum capacity of 0.06 kilowatt peak per square meter of the built-up land area."

"The built-up land area includes the area where a building touches the ground with its exterior wall, as well as roof overhangs that protrude beyond it."

14x12.5m house, and 9.2x7m garage = 239.4m² x 0.06 = 14.4kWp

That already adds up to quite a bit, I would not have thought so