Player housing isn't that bad of an idea but I think it would be more useful to have a clan area. Maybe you build a type of powerful weapon that can only be built there. Each of the clan members can contribute materials and glimmer towards it. Maybe have clan battles in the crucible. Either 3v3 or 6v6. Make a clan rank. When the clan rank progresses new things are unlocked. Maybe bonuses like extra glimmer and xp or something of equal use. Just an idea I just thought up. Edit-Maybe you can build a class item that has bonus stats? Maybe there are multiple things you can make that has different requirements.