Abstract: A device for fastening equipment parts such as photovoltaic panels on a sandwich or single-shell building envelope using a plurality of fastening elements (20, 20?) in the form of bolts, which can be supported at least by a connection part (30, 30?) and on a load-bearing part (12) of the building or the building envelope. If an outer shell (14) is present, the fastening elements (20, 20?) can be guided through the outer shell (14) and supported on the load-bearing part (12) and/or the outer shell (14). Each fastening element (20, 20?) can be positively engaged with the connection part (30, 30?) and/or, if present, with the outer shell (14) so as in each case to support the connection part (30, 30?) on the load-bearing part (12) and, if present, on the outer shell (14).