You can find out who lives at an address by searching the Electoral Roll. There are 2 versions. The open register and full register. The open register you can search online by clicking here
The Full register you can view by contacting the local Library or history centro. Contact them first to make sure they have the register as they may want you to book a time slot.
Anyone on the Full Register can tick a box and opt out from the Open Register. Some Councils may automatically tick boxes to opt addresses out from the open register.