Any new urban buildings in Berlin, the capital of Germany, must use photovoltaic roofs in the future to make solar power generation a norm; old buildings will also be retrofitted with solar photovoltaic systems, and new energy standards will be enshrined in federal law.

Any new urban construction, including all new construction and major roof renovations, will be mandatory to design solar photovoltaic power generation, and both apply to residential and non-residential buildings.

The plan is expected to turn 30 percent of Berlin's rooftops into solar roofs. According to Fraunhofer ISE forecasts, within the first five years of the programme, the ruling will save around 37,000 tons of CO2 per year, and Berlin's solar power generation is expected to increase by a factor of 40.

It is understood that Berlin's proposal to deploy solar photovoltaic power generation on buildings has been legislated as a powerful tool to promote the decarbonization of buildings.

The upcoming revision of the Renewable Energy Directive II and the energy performance of buildings will be key to ensuring that the same targets are replicated across the EU, ensuring that buildings fully contribute to the goals of the Energy System Integration and Retrofit Wave strategy. If Berlin's "Solar City" plan goes well, a series of measures is to achieve 4.4 GW of solar photovoltaic power generation, to meet a quarter of Berlin's electricity needs.