Building footprints in the form of polygons in three different informal settlements in Lima, Peru in geopackage layers. The locations of the settlements are Barrios Altos, El Agustino and José Carlos Mariátegui. The layer also contains semantic information with regards to the number of floors of the buildings and the thermal properties of the building envelope (lightweight, mediumweight, heavyweight) associated with the construction materials of the external walls and their thermal conductivity. The files can be uploaded to the freely accessible software QGIS (and other similar software packages) for editing and further use.