There are a variety of financial support options for low-barrier (re)building at federal and state level. You can read here which requirements have to be met and which subsidies are available.
With the aid of the Kreditanstalt für Wiederaufbau (KfW), the state promotes various public concerns, including housing construction. On the one hand, builders benefit from state subsidies such as the child benefit, on the other hand they can take out loans for energy-efficient construction.
The KfW Efficiency House 40 Plus is a classification for the energy efficiency of new buildings, which is accompanied by financial support options from the Reconstruction Loan Corporation (KfW). The requirements here are on the one hand the reduction of the primary energy requirement of the new building by 60% compared to an EnEV reference building and the equipment with a so-called "Plus Package", which includes various structural requirements for energy efficiency.
KfW 70, 55, 40 and 40 Plus provide information about the standards for new energy-efficient houses. This article sheds light on their requirements, costs, and price differences.
Wohnriester grants consist of government grants in the form of allowances and tax breaks. You can find out here which rules these are linked to.
The energy efficiency of new buildings has steadily increased in importance in recent years. Houses are divided into different KfW efficiency classes: KfW 70, KfW 55, KfW 40 and KfW 40 Plus. This article sheds light on the different standards, as well as their costs and price differences.