House extension drawings in Wandsworth

Plots, conservation areas and listed houses

Domestic gardens cover about 21.5 per cent of the borough in the national land-use data, and the garden is what the rear extension rule protects. Wandsworth has 46 conservation areas, and Historic England lists 312 entries in the borough.

Conservation area status can change the route for an extension, and a listed house needs its own consent for most alterations. We check the address first, because it decides whether the work is a notification, a certificate or an application.

Permitted development, prior approval or an application

Nationally, a single-storey rear extension is permitted development within these limits: 3 m (attached) / 4 m (detached) beyond the original rear wall, single storey. The larger home extension route reaches 6 m (attached) / 8 m (detached), single storey, height max 4 m; not on article 2(3) land or an SSSI, with a neighbour consultation.

Wandsworth granted 13 and refused 12 larger home extension applications in its latest published year, so the outcome here is close to even. Where the limits are met a Lawful Development Certificate in Wandsworth confirms it. For anything else, the application is drawn as in our planning drawings in Wandsworth.

How Wandsworth decides householder applications

Wandsworth decided 977 householder applications in its latest published year, granted 91.9 per cent and decided 92.4 per cent within eight weeks or an agreed extension. These figures cover all householder work, not only extensions, and they give no forecast for a single house.

What the drawings show and what they cost

A Wandsworth extension set includes existing and proposed plans, every elevation, a section through the extension and the location and block plans, with the retained garden dimensioned. Prices start at £695 with VAT included. A second chartered technologist checks every sheet and we redraw free until approval if the council asks for changes.

Once you have consent, the construction detail belongs in building regulations drawings in Wandsworth. They apply the Approved Document L limits, including: Windows, roof windows, rooflights and doors in an extension should not exceed 25% of the extension floor area plus the area of openings removed or covered. Notice to neighbours may also be needed: Adjacent excavation notice at least 1 month before work: within 3 m and deeper than the neighbour's foundations, or within 6 m and cutting a 45° line from their foundations.

Roofs and neighbouring councils

Wandsworth's SPD also covers roof extensions, so a loft and an extension are judged against the same guidance; see loft conversion drawings in Wandsworth. For single shapes, see rear extension drawings in Wandsworth and side return extension drawings. The borough overview is architectural drawings in Wandsworth. Next door, compare house extension drawings in Lambeth and in Merton.