https://www.maanmittauslaitos.fi/en

From the dataset abstract

NLS-FI INSPIRE Buildings Theme Dataset is a dataset depicting the Buildings covering the whole of Finland. It contains the following INSPIRE feature types: Building

The elements are updated weekly. The dataset is based on the NLS Topographic database: http://www.paikkatietohakemisto.fi/geonetwork/srv/en/main.home?uuid=cfe54093-aa87-46e2-bfa2-a20def7b036f. Id-attribute indicates the topographic database id for features (mtk-id).

The dataset is available via the NLS-FI INSPIRE Download Service (WFS) for Buildings Theme and it can be viewed via the NLS-FI INSPIRE View Service (WMS) for Buildings.

Source: NLS-FI INSPIRE Buildings Theme Dataset