Open geographic data

The City of Helsinki’s City Survey Services maintain interface services and publish the open datasets mainly through standardised interface services. The material is updated every weekday and covers either Helsinki or the larger Helsinki Metropolitan Area. City Survey Services is the largest producer of this data, but the service also includes other datasets from the city’s Urban Environment Division. Some forms of material (for example, elevation models) are only available in file format via the opendata.fi website or as downloads from the Helsinki Map Service. Information about the material’s methods of distribution can be found in the open data directory.

The coordinate system used by the City of Helsinki is ETRS-GK25 (EPSG:3879), and the height system is N2000. Data in file format has been produced in the city’s system, but you can use the interface services to request data in all coordinate systems supported by the services, of which there are dozens.

If you use the interface service continuously or on a large scale, City Survey Services will draw up an official customer agreement for you. In this case, the customer receives a service guarantee and support when first taking the service into use. The customer relationship also enables communication between the City Survey Services and the customer in the event of a failure, for example. Please contact the City Survey Services if you connect an interface service to the online service.