Would welcome any knowledge or advice on the following. Have a new apartment (off the plan), have tenants in, found out shortly after them moving in that a) we have a serious condensation problem which hasn't resolved even with the tenants following all of the instructions the builder has supplied us all with twice b) a nightclub opened up over the road and music now plays until about 3am (and people hang around in the streeth until later). Changing the windows to double glazing seems to be a (partial) solution to both issues, but - who "owns" the windows? The OC or half me/half OC? - do I need permission from the OC to change the windows? - can I ask the OC to pay half given the windows are at least half owned by them? Any other thoughts on the issue? Thanks in advance.