By surveying staff members of the borough administrations and the Berlin forestry agencies familiar with the material and with the areas involved, it was possible to obtain specific information on areas, with respect to:
- the location of areas (borough, neighbourhood, address/location description, coordinates),
- the property situation, and contact data if appropriate,
- existing (or former) and planned land use,
- type of impervious cover, and extent of its possible removal, and
- any need for coordination, obstacles to the planning process, etc.
On this basis, an initial compilation of potential areas for the removal of impervious coverage was developed. Further relevant information was linked to this area-related primary data by intersecting it with other geo-data available in the State of Berlin, in order to make this information easily accessible. In addition, the following available digital information was used:
- plots of land as per the Official Property Cadastre Information System (ALKIS), as of October 6, 2023,
- plots of land owned by the State of Berlin as per the Official Property Cadastre Information System (ALKIS), as of October 6, 2023,
- block map 1 : 5,000 (ISU5) of the Urban and Environmental Information System (ISU) of the Senate Department for Urban Development, Building and Housing, III D, as of 2020,
- Planning Advice for Soil Protection, as of August 13, 2018,
- areas of application of current and concluded development planning procedures, as of October 19, 2023,
- the Land-Use Plan (FNP), working map, as of May 11, 2023,
- the landscape planning procedure, as of 2013,
- protected areas under conservation law (Landscape Protection Law (LSG), Conservation Law (NSG), Habitat Directive (FFH), large-scale natural monuments), as of May 11, 2023
- neighbourhoods as per the Official Property Cadastre Information System (ALKIS), as of October 6, 2023, and
- standard land values (“Bodenrichtwerte”), as of January 1, 2023.
Areas were visually examined, and, where those limits did not coincide with lot boundaries, potential areas for the removal of impervious coverage were delimited, primarily on the basis of:
- digital orthophotos, aerial photography flights from 2002 to 2023,
- aerial photos, recorded between 1953 and 1999, and
- the Map of Berlin, scale 1 : 5,000 (K5), versions of 2008 to 2023.
In particular cases, an on-site inspection was carried out.