The whole spectrum — rear extensions, side returns, wraparounds, double-storey, basement digs. Planning-led design with detailed technical phase, ideal for victorian terraces in Clapham, Brixton, Herne Hill typical of Lambeth.
The whole spectrum — rear extensions, side returns, wraparounds, double-storey, basement digs. Planning-led design with detailed technical phase, ideal for victorian terraces in Clapham, Brixton, Herne Hill typical of Lambeth.
Housing stock in Lambeth: Victorian terraces in Clapham, Brixton, Herne Hill; Edwardian villas; 1930s and post-war estates in parts of Streatham; Georgian in Kennington.
Character: Mix of dense Victorian residential and post-war estate; strong conservation area coverage; generally design-led planning decisions.
Article 4: Borough-wide Article 4 for HMO conversions; plus office-to-residential restrictions.
Measured existing survey, photographic record, Article 4 and conservation check specific to Lambeth before we quote.
2–3 design options at concept stage — alternative layouts, glazing, roof forms.
Site location plan, existing and proposed plans, elevations, sections, D&AS where required.
Part L thermal, Part B fire, Part M accessibility, structural strategy.
Steel beam, foundation, lintel design. Chartered engineer sign-off.
Party Wall notices where needed; Thames Water Build Over Agreement where within 3m of a public sewer.
Single planning or regs submission.
Planning + building regs + structural.
Listed, conservation, complex sites.
Direct answers to the questions Lambeth homeowners ask every week about house extension drawings.
Start a free quote →Most standard extensions in Lambeth fall under Permitted Development — single-storey rear up to 3m (attached) or 4m (detached), side returns up to half the width of the house. However, Lambeth has Article 4 Directions that may remove these rights in specific streets, and flats, listed buildings and conservation areas always need full planning. We check PD eligibility before quoting.
Standard permitted development allows single-storey rear extensions up to 3m (attached house) or 4m (detached) in Lambeth. Larger extensions up to 6m/8m are allowed under Prior Approval (Class AA). Flats, listed buildings and Article 4 areas in Lambeth are excluded from these PD rights.
Our fixed-fee architectural package starts at £1,225 for a Lambeth extension (planning + building regs + structural). Typical Lambeth build costs are £2,400–£3,500 per square metre including VAT — so a 25m² side return extension is £60,000–£87,500 to construct.
Lambeth does not have a borough-specific basement policy beyond the national framework — basement conversions are generally permissible subject to structural, drainage and flood-risk considerations. Thames Water Build Over Agreements apply where you're within 3m of a public sewer.
Most Victorian terraces in Lambeth (particularly in Clapham Common) benefit from both — a side return extension infills the narrow side passage to create a wider kitchen, a rear extension projects back into the garden. A wraparound combines the two. We recommend the best option at the free site visit.
We cover every London borough with the same fixed-fee approach. If your property sits on a boundary, here are the neighbouring options.
We cover every architectural technology service in Lambeth with one chartered team.
From £840. A fixed-fee, end-to-end service — measured survey, scaled drawings, Design & Access Statement where required, Planning P...
From £840. A construction-ready drawing package compliant with every Approved Document — Part A structure, Part B fire, Part L ther...
From £1,225. Every loft type across every {location} roof line — dormer, mansard, hip-to-gable, L-shape, Velux. LDC or full planning ...
From £1,575. {location}'s most space-efficient loft solution when PD-route dormers are blocked. Our chartered team designs mansards t...
From £995. Turn your unused {location} garage into a bedroom, home office or open-plan kitchen-diner. Planning route assessment, fu...
From £1,950. Full architectural technology service for basement digs and cellar conversions in {location} — structural underpinning d...
From £350. Chartered structural engineer calculations for every residential intervention in {location} — steel beams, lintels, pad ...
From £450. End-to-end Party Wall Act 1996 service for {location} — Section 1, 3 and 6 notices, schedule of condition surveys, party...
From £1,225. London's most popular loft type — the full-width rear dormer. Planning or Permitted Development route assessed for your ...
Free quote in 60 seconds. Fixed fee from £1,225. MCIAT chartered.
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