Building footprints are a key component of many GIS applications, including morphological and street view based analysis. Crowdsourced data such as OpenStreetMap (OSM) is widespread but not consistently detailed enough to reliably extract footprints of individual buildings, while topographic building maps such as the Ordnance Survey MasterMap Topography Layer (MTL) may split footprints into multiple polygons or include constructions without an address. We propose a method to determine which topographic building polygons can be unambiguously matched to individual footprints of buildings with an address, to enable integration with address-based data sources such as transactions or energy performance certificates. The results suggest that this method recovers significantly more building footprints than what can be obtained from OSM.