During the last few years, both federal and state governments in Germany have mandated green initiatives and adopted legislation in different fields of law.

Based on federal regulation, municipalities are directly obliged to consider aspects of climate protection in creating zoning plans. According to Section 1(5), sentence 2 of the German Federal Building Code (Baugesetzbuch or "BauGB"), municipalities must create zoning plans that ensure a humane environment and protect the natural basis of life. However, according to Section 1a (5) BauGB, the aspects of climate protection must always be weighed up against other public and private concerns. In this regard, courts have ruled that aspects of climate protection do not take precedence in principle.

In contrast, German building law not only provides for a general obligation to consider climate targets, but it also makes specific suggestions as to how municipalities can integrate climate protection measures into zoning and development plans. For example, if the municipality draws up a zoning plan, it can determine if the municipal area should be equipped with certain installations that counteract climate change. In particular, the municipalities are authorized to regulate the generation, distribution or storage of electricity and heat from renewable energies. The regulation makes further specific proposals for the implementation of climate protection measures in sections 9 and 9 (1) No. 25 BauGB. For example, these measures propose that the municipality can stipulate the planting and maintenance of plants. Therefore, municipalities are free to specify a tree-planting pattern for parking lots or order the greening of buildings. Consequently, German building law provides for a variety of measures that empower the local government to enforce green initiatives.

However, German building law does not only empower municipalities to implement climate protection measures. It also empowers the developer. Section 248 BauGB gives the developer the right to oppose certain development plans if these would prevent climate protection measures. For instance, if the development plan stipulates a certain building height that is exceeded by the installation of solar panels, the installation may still be legal. It therefore makes it possible to use the development plan in the first instance and subsequently conduct energy-efficient retrofits even though it may violate the development plan. However, these options are limited. Every deviation from the development plan must be weighed against the interests of neighbors that might be affected by the deviation. This shows that climate protection in German building law cannot be enforced against all reason. It must always be set in relation to other interests.

On the level of the different German federal states (Bundesländer), governments support sustainable urban development by establishing sustainability regulations and promoting sustainable projects. However, each state pursues its own initiatives, which are adapted to the different local conditions. The states set up strategies with sustainable goals they want to achieve, finance sustainable projects and set up committees that continually redefine the objectives. Below are some examples pursued by German states:

• The government of Bremen developed a concept for a sustainable business park within its "green economy strategy." The aim is to enable the businesses located there to operate sustainably and ecologically. To achieve this goal, the business park itself will provide for sustainable infrastructure. For example, the park's energy supply system is based on renewable energies. Moreover, all types of water (rainwater, wastewater from production, process water) shall be directed into a biological recycling process so that they can be reused. In addition, extensive greening of the building roofs is planned, and light emissions should be minimized.
• Hesse launched the "Growth and Sustainable Renewal" funding program. The project aims to promote sustainable urban development by involving local stakeholders and granting subsidies based on sustainability considerations. Municipalities may receive subsidies for the financing of sustainable measures (e.g., re-naturalizing ditches, connecting existing green spaces, upgrading green spaces, additional greening), evaluated based on the guidelines issued by the state for promoting sustainable urban development. Currently, 45 different projects are part of the program.