Example real estate management as object-based model

An object-based description is quite typical for the real estate application area. The official real estate cadaster - which historically served as a basis for the taxation of ownership of land and buildings - comprises basic geoinformation in object-based modeling and geometrically stored as vector data, especially on parcels, buildings and actual land uses as well as property information according to the land register. The basic geoinformation is now verified in the Official Real Estate Cadastre Information System (ALKIS), which is described in the documentation on modeling geoinformation in official surveying (GeoInfoDok, AdV (2009)). The legal basis is provided by the laws on state surveying and basic geoinformation of the individual federal states (e.g. VermKatG NRW). The transfer of the previous systems ALK (Automated Real Estate Map) in combination with the Automated Real Estate Book (ALB) to the new ALKIS has been carried out in all federal states. For the status of the introduction, see the activity reports of the AdV (e.g. AdV Tätigkeitsbericht 2017/2018).

All data are recorded digitally and are kept in geometrically and topologically correct form together with the property and usage data in databases. From this, the known extracts/plans can then be generated again in written or graphical form. An architect or building owner can retrieve the excerpt required for his construction planning, e.g. in the form of a site plan on paper or digitally via the Internet. On such a data base residential buildings are then to be accomplished evaluations, in order to answer e.g. the following questions:

• What is the average floor area of residential buildings?
• Which residential buildings belong to the owner Bill?
• Which residential buildings are within 500m of the given location?

The results of these evaluations can be reproduced as numerical values, in tables, in diagrams or also in cartographic representation forms.