Step 1: Find locations, land use and floor areas of buildings
Goal: Find the locations, land use specification and floor areas for all buildings of a municipality/city.
→ The locations of the buildings enable the spatialisation of the material stock, meaning that it can be illustrated on a map (and by materials) for the entire municipality. Typically, the land use of the building, such as for use as retail, office, residential space etc., is provided with the location as well. (There may be cases where a building has multiple uses, but in this step a single, predominant land use for each building is identified). Further, the floor areas are needed to be able to calculate the amount of materials, together with the material composition (from Step 3).
- Contact the local or national cadastre: Ask for files on land use and building footprint/geometry for the buildings of the municipality. In a number of cases, these two pieces of information are grouped in one database.
- If you can get the data, move on to the next point on the list.
- If you can not get the data from them, you can try to (1) find the public sources or (2) get the data from OpenStreetMap, see below.
- Review the obtained data: Oftentimes the data come in the form of a GIS shapefile with different attributes. You should review the data and check that at a minimum, it contains information on:
- buildings with unique identifiers
- type of land use (retail, office, residential etc.)
- year of construction
- gross floor area in m2
- height (or number of stories)
In addition, it could have information on the number of façades and the latest year of renovation for each building in a city that can later also be useful. In case not all attributes are available, they can be enriched with other datasets.
Example: In the case of Apeldoorn, a city in the Netherlands, the building information is available from the Dutch cadastre and can be easily accessed. The heights of the buildings were not available, so we enriched the dataset with the 3D BAG dataset, which has open 3D building data, with a common unique identifier.
Aside from the cadastre, there are other sources for shapefiles that can be made use of, of which we have collected a few in the Data sources section.
Getting data from OpenStreetMap
If the data does not exist or cannot be derived from the cadastre or a similar institution, building footprints and in some cases also the building use (residential, commercial, industrial etc.) can be extracted from the OpenStreetMap (OSM). However, it should be taken into account that data from this source will be bottom-up and collaborative and not an exhaustive list for all buildings, whose classification may conflict with urban planning.
- You can use the OSM Buildings viewer to view your local situation, including the footprints and the typologies. For example, this is the view for Bodø: https://osmbuildings.org/?lat=67.27986&lon=14.38453&zoom=15.0&tilt=30
- Use the Overpass Turbo API to extract the data. For example, to extract the buildings from Bodø this would be the query: https://overpass-turbo.eu/s/1iOT