An extension or addition to your house is considered to be permitted development, UNDER PLANNING LAW subject to the following limits and conditions
NB – You will still probably need extension plans drawn / extension plans prepared to comply with Building Control regulations
IF it is:-
No more than half the area of land around the “original house” would be covered by additions or other buildings.
No extension forward of the principal elevation or side elevation fronting a highway.
No extension to be higher than the highest part of the roof.
Single-storey rear extension must not extend beyond the rear wall of the original house by more than three metres if an attached house or by four metres if a detached house.
Maximum height of a single-storey rear extension of four metres.
Extensions of more than one storey must not extend beyond the rear wall of the original house by more than three metres.
Maximum eaves height of an extension within two metres of the boundary of three metres.
Maximum eaves and ridge height of extension no higher than existing house.
Side extensions to be single storey with maximum height of four metres and width no more than half that of the original house.
Two-storey extensions no closer than seven metres to rear boundary.
Roof pitch of extensions higher than one storey to match existing house.
Materials to be similar in appearance to the existing house.
No verandas, balconies or raised platforms.
Upper-floor, side-facing windows to be obscure-glazed; any opening to be 1.7m above the floor.
On designated land no permitted development for rear extensions of more than one storey.
On designated land no cladding of the exterior.
On designated land no side extensions.