Guide to Planning Permission
There is no need for planning permission if :
- 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.
- Maximum depth of a single-storey rear extension of three metres for an attached house and four metres for a detached house.
- Maximum height of a single-storey rear extension of four metres.
- Maximum depth of a rear extension of more than one storey of three metres including ground floor.
- 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.
More information can be found on the planning portal interactive house by clicking here.
Guide to Porches
The planning rules for porches are applicable to any external door. You need to apply for planning permission when:
- The ground floor area (measured externally) would exceed three square metres.
- Any part would be more than three metres above ground level (height needs to be measured in the same way as for a house extension).
- Any part of the porch would be within two metres of any boundary of the house and the highway.
Guide to Building Regulations
Certain buildings are exempt from obtaining Building Regulation approval.
- Small detached single storey buildings such as garages, sheds and greenhouses which contain no sleeping accommodation and which are: not more than 30m sq in floor area and;
- built of substantially non-combustible materials if the building is less than 1m from the boundary (this does not apply if the floor area is not more than 15m sq)
- A greenhouse or conservatory built at ground level with a floor area of not more than 30m sq. Separation to remain between conservatory and house i.e. doors or windows, (glazing at low level or in doors and sidelights must be carried out in safety glass as recommended by the manufacturer or supplier).
- A carport open on at least two sides, the floor area of which does not exceed 30m sq.
- A porch where the floor area does not exceed 30m sq. Separation to remain between porch and house.
All other building work will require building regulation approval.
Other Building Reg Exceptions :
- Less than 30m² Conservatory
More information, and all the approved documents, can be found on the planning portal here.
- A volume allowance of 40 cubic metres additional roof space for terraced houses*
- A volume allowance of 50 cubic metres additional roof space for detached and semi-detached houses*
- No extension beyond the plane of the existing roof slope of the principal elevation that fronts the highway
- No extension to be higher than the highest part of the roof
- Materials to be similar in appearance to the existing house
- No verandas, balconies or raised platforms
- Side-facing windows to be obscure-glazed; any opening to be 1.7m above the floor
- Roof extensions not to be permitted development in designated areas**
- Roof extensions, apart from hip to gable ones, to be set back, as far as practicable, at least 20cm from the original eaves
- The roof enlargement cannot overhang the outer face of the wall of the original house.
*Bear in mind that any previous roof space additions must be included within the volume allowances listed above. Although you may not have created additional space a previous owner may have done so.
**Designated areas include national parks and the Broads, Areas of Outstanding Natural Beauty, conservation areas and World Heritage Sites.
Confusing to people with no experience is the difference between building regulations drawings and planning permission drawings. Depending on what the development proposal is, one or both may be required. Below is a rough guide.