Building Age in Residential Development 2016
As described in the chapter Statistical Base, the recorded stock stems from two data sources, of which the CENSUS accounts for the far larger share.
The CENSUS survey unit used in the record of the building and housing stock (cut-off date 9 May 2011) is one individual building.
The Statistical Office for Berlin-Brandenburg is responsible for all data analysis of the 2011 building and housing count. The responsible “Division 44 P – Census” summarised building-related information in the block map of the Information System City and Environment (ISU5/ISU50, spatial reference Environmental Atlas), dated December 2010.
Since all individual data points are subject to statistical confidentiality according to Article 16 of the Federal Statistics Act (BstatG), it had to be ensured that no inferences on individual cases could be made during the analysis. Therefore, the complete data catalogue could not be displayed under all circumstances. It is prohibited to publish cases with just 1 or 2 residential buildings recorded per reference unit. This concerns some 1,450 blocks and block segments; i.e. less than 1 % (0.89 %) of the recorded total stock of residential buildings in the worst case. The remaining 99 % of residential buildings are spread across more than 14,400 blocks and block segments. According to the Census survey on the cut-off date, the remaining ~10,500 areas of the ISU block map contain either no building stock, exclusively non-residential buildings or only 2 or fewer residential buildings.
The building age of the recorded stock is aggregated in groups of decades termed “Building age groups”, in order to be able to indicate the number of buildings per group for each area. In addition, the year of construction of the oldest and the newest building respectively is indicated in the total stock of the block or the block segment for each area.
Furthermore, the data catalogue contains information on the distribution of the stock across 4 building types per single area (and relating to the years of origin 2010 and older) independently of the age classification (cf. CENSUS 2011 – Buildings and dwellings):
- Detached house (free-standing building, irrespective of whether it is a single-family or multi-family house)
- Duplex (building which is built against another building, irrespective of whether they are single-family or multi-family houses)
- Row house (building which is built against at least two other buildings, irrespective of whether they are single-family or multi-family houses. The buildings do not have to be of the same construction type; they do not have to be completely in line or of the same height. Terminal row houses are included.
- Other building type (all types of buildings which are not a detached house, duplex or row house, and all types of inhabited accommodation).
The distribution of building types does not allow for a direct conclusion as regards the building age groups.
All data is based on information by the ‘respondents’ obliged to provide information, which included all owners, managers and other parties entitled to disposal and use within the framework of this survey. In view of the very large catalogue of data, it was inevitable that errors occur in individual cases, despite taking great care to achieve a complete and up-to-date result. This could have had several causes:
- Erroneous owner statements
- Misinterpreted definitions (the year of reconstruction had to be stated for destroyed buildings)
- Error in the reading of occupancy
- Statistical tracking of missing values.
Therefore, during the analysis of special issues (“all buildings older than 200 years”), a check should always be run in the Geoportal using appropriate sources of information (e.g. aerial photographs, historical maps “Berlin um…” (Berlin around…) or the map of monuments in Berlin).
The CENSUS data was complemented by data on building completions for residential buildings for the 2011 – 2015 half-decade (cf. Statistical base). As the data on building completions is updated annually, it will be feasible to also integrate the entire 2011 – 2020 decade at an appropriate point in time. In regards to data protection law, the obligations of the Federal Statistics Law also apply here. Overall, the inclusion of data from the law on building statistics (HBauStatG) facilitated the spatial inclusion of about 8,800 additional buildings.
The predominant building age group was the decade that covers the largest percentage in the area. Using the data display for factual data in the Geoportal, the shares of the other groups and further information can be accessed. Should several groups possess an equal share, a “mixed building age group” is displayed.