Pitched roof extensions

A pitched roof extension uses a sloping roof, either a lean-to against the house or a gable or hipped roof, finished in tiles or slate to match the existing building. It is the traditional choice for cottages, period houses and anywhere the extension needs to blend in.

A pitched roof sheds rain quickly and can include roof windows or a vaulted ceiling inside. The main constraint is height: a lean-to has to start below the first-floor windows, which limits how deep the extension can be.

What is included

• Roof design matched to the existing pitch and tiles
• Vaulted ceilings or flat ceilings with storage above
• Roof windows positioned for light and ventilation
• Lead or proprietary flashings to the main wall
• Insulation to current building regulations

Who it suits

• Traditional, period and rural houses
• Conservation-sensitive streets
• Homeowners who prefer a vaulted ceiling

Design advice

Matching tiles is harder than it sounds. We source reclaimed or closest-match tiles where the originals are no longer made and agree samples with you before ordering.

How much does it cost?

National guide prices including VAT at 20%. Build cost only; design, structural and council fees are extra. Your area page shows prices adjusted for your region.

Planning rules across the UK

England

In England a single-storey rear extension can usually go up to 3 m beyond the original rear wall of a semi-detached or terraced house, or 4 m on a detached house, without a planning application, provided it is no more than 4 m high, keeps eaves to 3 m within 2 m of a boundary and, with other buildings, covers no more than half the land around the original house. The larger home extension prior approval scheme raises those depths to 6 m and 8 m, with neighbours notified and a 42-day decision.

Wales

In Wales a single-storey rear extension can usually project up to 4 m beyond the rear wall without a planning application, if it is no more than 4 m high, keeps eaves to 3 m and overall height to 4 m within 2 m of a boundary, and covers no more than half the land around the original house. Wales has no larger home extension prior approval scheme.

Scotland

In Scotland, householder permitted development rules (Class 1A for single-storey ground-floor extensions and Class 1B for extensions of more than one storey) allow some smaller extensions without a planning application, within limits on depth, height and distance from the boundary. Conservation areas and listed buildings are more restricted. Separately, almost every extension needs a building warrant from the council before work starts.

Northern Ireland

In Northern Ireland the Planning (General Permitted Development) Order 2015 lets some single-storey rear extensions go ahead without planning permission, up to 3 m on a semi-detached or terraced house and 4 m on a detached house, within height and boundary limits. Larger, side and two-storey extensions normally need planning permission from the council, and building control approval is separate.

Building regulations and neighbours

Building regulations approval is separate from planning. In England you can use the council's building control team or a registered building control approver; a full plans application gets the drawings checked before work starts, and the inspector signs the work off with a completion certificate.

In England and Wales, if the work involves a shared wall, building on the boundary, or digging foundations within 3 m (sometimes 6 m) of a neighbour's building, the Party Wall etc. Act 1996 applies and notice must be served before work starts: two months for work to a party wall, one month for new walls on the boundary and for excavations. Scotland and Northern Ireland have no Party Wall Act.

Questions about pitched roof extensions