Do I need planning permission for a rear extension?

Many single-storey rear extensions can be built without a planning application. These are the main limits to know about.
Planning drawings vs building regs drawings: what is the difference?

They are two different sets of drawings, for two different approvals. Here is what each one is for and when you need it.
Five things to check before planning a loft conversion

Headroom, stairs, fire safety and a couple of other things worth knowing before you get quotes for a loft conversion.