Brick, stone and rendered block: cost breakdown
Brick garden walls — the most common specification in London — are priced by the linear metre at a given height. A single-skin half-brick wall (102.5mm) at 1.0m height costs £300–£500/lm; at 1.8m height with piers at 1,800mm centres costs £450–£700/lm. A double-skin full-brick wall (215mm) at 1.8m costs £650–£1,000/lm. Brick specification matters significantly for period properties: London stock brick (yellow-brown London handmade stock or machine-made equivalents from suppliers including Ibstock, Michelmersh, Charnwood) is the appropriate choice for Victorian and Edwardian terraced gardens across inner London. Engineering brick (Class B blue or red) is used for boundary walls subject to high moisture exposure — below damp-proof course level or in flood-prone areas. Reclaimed London stock from demolition salvage suppliers (Lassco, Hutton & Rostron) adds 20–40% to material costs but produces the most appropriate aesthetic for conservation area gardens. Natural stone walls — random rubble limestone or sandstone — cost £600–£1,400/lm and suit period properties in boroughs with Ragstone or limestone building traditions. Rendered blockwork (dense aggregate block with smooth or sand-faced render) costs £350–£650/lm and suits contemporary garden designs.
Planning permission and height rules
Garden wall planning rules in England are set by the Town and Country Planning (General Permitted Development) Order 2015 (as amended). The key rules are: walls up to 1m in height adjacent to a highway (road, footpath, public right of way) are permitted development — walls over 1m on a highway boundary require a householder planning application. Walls up to 2m in height elsewhere in the garden are permitted development — walls over 2m require planning permission. In conservation areas, permitted development rights for boundary treatments are commonly removed by Article 4 Directions, meaning any new garden wall — even under 1m — may require planning permission. The Royal Borough of Kensington & Chelsea, Camden, Islington and Westminster have Article 4 directions covering boundary treatments across large residential areas; check with the local planning authority before starting work. Listed building curtilages require Listed Building Consent for any new boundary wall, regardless of height.
Party wall and boundary considerations
A garden wall built on or astride the boundary between two properties is a 'party fence wall' under the Party Wall etc. Act 1996. Work on an existing party fence wall, or construction of a new wall on the boundary line, requires a Party Wall Notice served on the adjoining owner at least 2 months before work starts. A wall built entirely on your own land, set back from the boundary line, does not engage the Party Wall Act — though it must not encroach over the boundary line at any point, including foundations. Foundation projection: a 215mm brick wall requires a 450–600mm wide concrete strip foundation; this projection often extends under the boundary line even when the wall itself is set back. Agreement with the neighbour for temporary access to dig and pour foundations adjacent to the boundary is advisable before work starts. Where the wall replaces an existing fence or hedge, confirm the exact boundary position with the title deeds and Land Registry plan before setting out — boundary disputes arising from incorrectly positioned walls are expensive to resolve.
