I believe this building should be referenced with the following attributes:

addr:housenumber 	1065
addr:street 	Chaussée d'Alsemberg - Alsembergsesteenweg

source: https://www.facebook.com/Open-Free-Go-Uccle-asbl-164009987416434/?ref=page_internal and a visit on site. It is a community use of a building that belongs to the railways.