Sustainability in the development plan – A new standard for new construction.

Will the planned changes to the German Building Code (BauGB) lead to sustainable housing construction?

When it comes to the term sustainability, people rarely question what it actually means. A simple Google search can be helpful here, and lo and behold, sustainability does not only refer to environmental protection and securing resources for the future. Rather, there is also social sustainability, which aims to prevent poverty and create humane living conditions. Housing construction has been at a standstill for many years. In the Federal Republic of Germany, there is an estimated shortage of 550,000 homes. Those that are available have become unaffordable for the majority of people, especially in metropolitan areas. What can the state do about this, especially the federal government itself, with only limited legislative powers in public building law? In fact, there have been various initiatives at the federal level to remedy the housing shortage. On the one hand, a draft bill on building type E was drawn up, which was intended to make construction cheaper by eliminating many so-called recognized rules of technology. In addition, there is an initiative to clarify what legally prevents simple and inexpensive construction, and most recently, the planned amendment to the Building Code in July 2025 under the keyword “Bau-Turbos” (construction turbo). Let's take a look at whether the changes can actually bring about social sustainability.

So far, only a draft bill to amend the Building Code has been presented, which was approved by the Federal Cabinet on June 18, 2025 (Act to Accelerate Housing Construction and Secure Housing). The legislative process is expected to be completed in fall 2025. The planned amendment has four objectives, namely

• to accelerate housing construction,
• to facilitate noise protection regulations,
• to extend conversion protection, and
• to extend the provision on areas with a tight housing market.

The new Section 246e of the Building Code is intended to serve as a kind of experimental clause allowing deviations from development plans if the deviation is compatible with public interests, taking into account the interests of neighbors. To this end, there will be an Annex 2 that sharpens public interests, among other things by stipulating that the projects must not cause any additional significant environmental impacts. The regulation is limited until December 31, 2030, and only applies to residential construction, the expansion or alteration of existing residential buildings, and changes of use for residential purposes. However, the municipality must agree to this (Section 36a BauGB). The outer area can also be included, provided that it is spatially connected to areas in accordance with Sections 30 ff BauGB (Section 246e (4)). Furthermore, the requirements for integration in Section 34 (1) BauGB are relaxed, but this also requires the approval of the municipality. Finally, Section 9 (1) No. 23 BauGB is amended. In future, deviations from the TA-Lärm values may be permitted in justified cases. Finally, the possibility for municipalities to designate areas with a tight housing market by means of a statutory order is extended until December 31, 2030 (Section 250 (1)). This will continue to make conversions difficult. 

The regulations are limited by the federal government's limited legislative powers in public building law. They are also subject to municipal approval, which stems from the municipalities' constitutional right to perform self-governing tasks under Article 28(2) of the Constitution. Nevertheless, they can be expected to have a significant impact on the expansion of the housing market. The construction of rental housing has so far failed not only because of the issue of profitability, which was mainly caused by the sometimes absurd regulations in the state building codes on fire protection, parking spaces, accessibility, etc., but also because of a lack of building land. Industrial estates were always too close, the land was already located in the outer area, the project did not fit into the unplanned inner area, or stipulations in the development plan, particularly regarding floor area ratio, did not allow for expansion. The legislature is now attempting to mitigate the latter obstacles. This should also provide an incentive for state legislators to “declutter” state building regulations. 

Investors should first start looking for suitable sites that meet the requirements of the amendment.

Since municipalities must grant approval for housing projects that do not yet fit in, do not comply with the provisions of the development plan, or are located in the adjacent outer area, the difficulties for housing construction are likely to be shifted from the legislative to the executive branch. An unlawfully refused approval refers investors – as has been the case up to now – to lengthy legal proceedings with an uncertain outcome, which makes almost every project unattractive. Furthermore, there are still a large number of legal regulations that make housing construction difficult. Particularly in adjacent rural areas, questions arise regarding environmental compatibility (UVPG), the existence of an impermissible encroachment on the natural and landscape features, or general and specific species protection (BNatSchG). In unplanned inner areas, it is still possible to argue whether a project fits in with the character of the immediate surroundings within a connected built-up district or not. Whether and which neighboring interests may be affected also remains in the usual unpredictable realm.

The draft law can only be the beginning of the solution to the rapid construction of affordable housing. The reduction of essential building standards, which the federal government is also striving for, lies largely outside its area of competence, namely in the state building regulations. Apart from building type E, which is to be implemented primarily through civil law measures, the biggest obstacles lie in excessive building code requirements for buildings and thus in the legislative competence of the states. In addition to the requirements of the state building regulations and the Model Administrative Regulations for Technical Building Regulations (MVV TB), which usually elaborate on them, there are countless so-called “generally accepted rules of technology” that have so far been regarded by the civil courts as always applicable, without the contracting parties having expressly regulated this. The problem with this is not only that some of these rules are published without any scientific basis, but also that there is no evaluation of their usefulness by government agencies. No one knows exactly what is included in the generally accepted rules of technology. If you ask the relevant trade circles, they will usually refer to DIN standards, and in most cases also to VDE standards. Regardless of the sheer number of DIN and VDE standards alone, even simple manufacturer or processing guidelines can be considered generally accepted rules of technology. This is despite the fact that they are by no means written by manufacturers with the aim of providing an objective representation of what is necessary or sensible in terms of construction technology, but exclusively in their own interests.

Companies that have already identified areas that are suitable for residential construction in accordance with the amendments to the BauGB should first contact the municipality and the building permit authority to determine whether and to what extent they share the same views on this matter. These planning law issues can be clarified in preliminary proceedings.

Another way of securing the requirements under building law is to conclude an urban development contract between the investor (project developer) and the planning municipality for the preparation of a so-called project-related development plan. Such a contract is commonly referred to as an implementation contract and is a contract under public law.

In the broadest sense, it is a mutual contract. However, the consideration provided by the municipality does not consist in the enactment of a corresponding project-related development plan (Section 1 (3) sentence 2 BauGB), but only in the fulfillment of obligations to cooperate in order to obtain a project-related development plan (drafting resolution, early and formal participation, weighing process, etc.).

Prerequisites for such a contract:

• Sovereignty of the project developer over the required land (§ 12 (1) BauGB),
• Feasibility of the project developer (§ 12 (1) BauGB),
• Coverage of development costs (§ 12 (1) BauGB).

In the case of a project-related development plan, the investor usually initiates the urban land-use planning procedure.  He presents his project to the municipality and suggests that a project and development plan be drawn up, which will later become the subject of the project-related development plan.

Conclusion and outlook

The amendments and additions proposed in the draft bill are a first step toward quickly creating affordable housing. They pave the way for new building land. The new coalition's approach of “simplifying” construction and, as a result, ensuring the creation of affordable housing must aim to lower legal building standards in addition to technical building standards. The former could be achieved by the federal government through an amendment to civil law, for which it has concurrent legislative power under Article 74(1)(1) of the Constitution. If the big push is to succeed, the federal government would have to commit to determining the technical standards itself. The small solution to the big challenge could be to draft a nomenclature of technical rules and classify them into the areas of “safety-relevant” and “comfort features.” The big solution would mean that the federal government, for example, through its Federal Institute for Materials Research and Testing, would set genuine, validated technical standards. Reducing the legal standards in state building codes, on the other hand, can only succeed if the federal government also convinces the states to remove excessive standards from their state building codes. Companies in the real estate industry should therefore work with their associations to develop legislative proposals aimed at streamlining building code requirements for residential buildings.