With City Council Resolution 0238/2021 of February 10, 2021, the administration was commissioned to conduct an expert assessment of where the conditions for a social preservation statute (milieu protection statute) are met in Mainz city center, with a particular focus on the Mainz-Neustadt and Mainz-Altstadt districts.

The first step in the process of examining the conditions for a social preservation statute is the preliminary investigation (rough screening), which was carried out from June 2023 to May 2024 with the help of the expert office "Landesweite Planungsgesellschaft mbH (LPG mbH)" from Berlin in selected areas of Mainz Neustadt, Altstadt, and Oberstadt. To this end, the application requirements of upgrading potential, upgrading pressure, displacement potential, and change movements were examined using a system of indicators. In addition, the building and usage structure was analyzed by means of a site inspection in order to exclude areas that are fundamentally unsuitable for a social preservation statute (including uninhabited blocks, new residential buildings, green and open spaces, areas for trade, services, commerce, industry, and public use). As a result of the preliminary investigation, two suspected areas, "Mainz-Neustadt and Mainz-Altstadt-Nord" and "Mainz-Altstadt-Süd," were identified for which an in-depth investigation was recommended.

On May 15, 2024, the city council passed a resolution to draw up a social preservation statute for each of the suspected areas "Mainz-Neustadt and Mainz-Altstadt-Nord" and "Mainz-Altstadt-Süd."

The second, current step in the process is the in-depth investigation of the two identified suspected areas (investigation areas). The conditions for application are being examined in more detail, in particular to ensure legal certainty in the potential implementation of the statute. The in-depth investigation will determine the interrelationships between the building and housing stock, the local housing market, the supply and demand for social infrastructure, and the composition of the resident population in the two investigation areas. If the conditions for application are met and there are urban planning reasons that make it necessary to preserve the composition of the population, as otherwise negative urban planning consequences are to be feared, the enactment of a social preservation statute is recommended.

The two study areas, "Mainz-Neustadt and Mainz-Altstadt-Nord" and "Mainz-Altstadt-Süd," had previously been identified in a preliminary study ("rough screening") in selected areas of Mainz-Neustadt, Altstadt, and Oberstadt. In order to justify the enactment of a social preservation statute in a legally secure manner, a representative household survey is required in the two study areas "Mainz-Neustadt and Mainz-Altstadt-Nord" and "Mainz-Altstadt-Süd," among other things. This household survey was conducted from January 20 to February 16, 2025. The aim was to gather information on the housing and living situation by involving as many residents as possible.

The state capital of Mainz commissioned Landesweite Planungsgesellschaft mbH (LPG mbH) from Berlin to conduct the survey. In mid-January, 10,000 randomly selected households from the two survey areas received a questionnaire that could be completed in writing or online. The corresponding website and an access code were provided on the questionnaire. Participation in the survey was voluntary, and the information provided was anonymized.

The survey collects

• household-related data (e.g., household size, length of residence, and satisfaction with housing),
• housing-related information (e.g., apartment size, amenities, and rent), and
• neighborhood-related aspects (e.g., use of social facilities and neighborly coexistence).

During the budget survey period, the state capital of Mainz, together with LPG mbH, held an information event for citizens on February 11, 2025, from 7:00 p.m. to 8:30 p.m. in the Great Hall of the Wolfgang Capito House (Gartenfeldstraße 13-15, 55118 Mainz). Here, citizens were able to find out about the procedure for the in-depth investigation, the budget survey, the possibilities and limitations of social preservation law, and were welcome to ask questions.