Building Age in Residential Development 2016
There is no comprehensive data catalogue available in Berlin yet that covers the topic of “building age / building age groups” encompassing all building types. This will not be possible in the future either, due to the lack of information on all non-residential buildings of the whole city. Based on current knowledge, this matter could only be revised fundamentally and completely with extreme effort.
Thus, the city’s building stock for the present map was inevitably limited to residential buildings, as there was no data available on the age of non-residential buildings.
The complete building stock listed in ALKIS (ALK before 1 December 2015), the Official Property Cadastre Information System, comprises about 320,000 residential buildings and some 230,000 non-residential buildings of various uses (SenStadtWohn n.d.). In addition, there is a building stock of about 73,000 units which is not recorded in ALKIS, including smaller buildings such as summer houses, garages and the like (cf. also map “Versiegelung” (01.02) (Impervious Soil Coverage (01.02)), SenStadtWohn 2017 (only in German)). Although the majority of the building stock was assessed in the representation of residential buildings, a relevant share of about 40 % of the total stock cannot be taken into consideration. This must be taken into account especially for representations of predominantly non-residential areas, such as mixed areas, areas with industrial/commercial uses but also blocks, such as Zoologischer Garten and Tierpark Friedrichsfelde, which also contain a (possibly small) residential building stock and which are thus part of the data used here. Using the data display for factual data in the Geoportal, the local total number of recorded buildings can be displayed.
The results of the EU-wide Census survey, a population census (Census 2011) that takes place every 10 years starting in 2011 (cut-off date 9 May 2011) constitute the central statistical base for the residential building stock in Germany. The subject area “Gebäude und Wohnungen” (Buildings and dwellings, CENSUS 2014, (only in German)) is part of the CENSUS database. It comprises characteristics of various types (ownership, building type, heating method, number of dwellings and housing) and the year of construction. The year of construction is the year a building is ready for occupancy. For buildings that have been completely destroyed and have been reconstructed, the year of reconstruction is considered the year of construction. This approach is clearly different from representations that emphasise urban development, for example that of Aust 1994. This record assigns buildings that were newly erected in the course of reconstruction after the Second World War their original year of construction if the old architectural style was taken up again. This process differs from that used in the CENSUS 2011 survey that emphasises the technical condition of the building. Consequently, the summaries based on time are rarely identical, as representations according to construction eras and those according to calendar decades do not completely correspond as one would expect.
The CENSUS recorded all buildings with any share of living space, i.e. also including buildings with a predominant share of shops and offices. The survey criteria are very differentiated, rendering permanently inhabited houseboats and summer houses part of the total stock, for example.
Since the analysis of the CENSUS database was subject to data protection considerations on a very detailed level concerning blocks and block segments, it was impossible to provide information on about 1,400 areas containing only 1 or 2 residential buildings. This limitation concerning forestry offices or restaurants in recreation areas with a share of living space for example, did not affect the analysis purpose of the map, which was to provide an overview of the building age structure including the residential building stock.
In order to close the time gap which resulted from the CENSUS survey date of 9 May 2011, data from the newly constructed residential building stock for the period from 1 January 2011 to 31 December 2015 was used from the information on the completion of buildings in connection with the law on building statistics (HBauStatG), recorded by the Statistical Office for Berlin-Brandenburg.