Drupal Commerce uses Address Field for its billing information. Street addresses are implemented as
Address 1 and
Address 2 lines. No other fields will be added to the module, since they want to keep it simple and follow the xNAL standard.
So how are people doing validation of user input? Specifically, how do you make sure they don't forget the housenumber? This happens, and it means extra work for the shop contacting the customer if it's noticed in time, otherwise an undeliverable package will be sent.
One solution would be a separate required field for house number, but I haven't seen a clean way of doing that (see e.g. this). Or perhaps dynamic validation of the Address field. So what are Drupal Commerce shops using? Any examples or recommended approaches?