House Extensions & Loft Conversions in Richmond

LCCL Construction is a design and build company based in Finchley N3, working in Richmond for over 20 years. One team, one contract: architects, structural engineers, project managers and builders coordinated by LCCL take your project from first sketch to handover.

Richmond, East Sheen and Kew mix Victorian terraces with larger Edwardian and 1930s semis and detached houses: wraparound extensions, hip-to-gable lofts and full renovations alongside the usual side returns. Richmond was named among London's best places to live in 2026.

What it costs in Richmond

The final figure depends on postcode, access and site conditions — the instant estimate applies your area. Guide ranges for 2026, design and build inclusive (architecture, structural engineering, planning or LDC, construction, project management and building control). Every project is surveyed and priced individually.

• Velux loft: £32,400 – £50,400 inc. VAT (£27,000 – £42,000 + VAT)
• Rear dormer loft: £56,400 – £80,400 inc. VAT (£47,000 – £67,000 + VAT)
• L-shaped dormer: £58,800 – £98,400 inc. VAT (£49,000 – £82,000 + VAT)
• Hip to gable: £60,000 – £114,000 inc. VAT (£50,000 – £95,000 + VAT)
• Mansard: £76,800 – £148,800 inc. VAT (£64,000 – £124,000 + VAT)
• Rear extension: £42,000 – £90,000 inc. VAT (£35,000 – £75,000 + VAT)
• Side return: £42,000 – £93,600 inc. VAT (£35,000 – £78,000 + VAT)
• Wraparound: £72,000 – £153,600 inc. VAT (£60,000 – £128,000 + VAT)
• Double storey: £90,000 – £198,000 inc. VAT (£75,000 – £165,000 + VAT)

Kitchen on top of the structure, supplied and fitted: +£9,000 – £87,360 inc. VAT (£7,500 – £72,800 + VAT) depending on size and specification. Basements: cellar refit £54,000 – £114,000 inc. VAT (£45,000 – £95,000 + VAT), lowering £114,000 – £216,000 inc. VAT (£95,000 – £180,000 + VAT), new dig £216,000 – £360,000 inc. VAT (£180,000 – £300,000 + VAT)+. New build: £2,200 – £4,500 per sqm (zero-rated for VAT).

A recent LCCL project near Richmond

Weech Road, Hampstead NW6 — penthouse duplex loft conversion

A top-floor flat turned into a penthouse duplex: the kitchen and living space moved up into the new loft, two new bathrooms, an extra bedroom and views across to the Shard, the London Eye and Parliament. LABC Building Excellence Awards 2026 London Regional Winner — Best Conversion or Alteration to an Existing Home.

See the project

Planning in Richmond

Richmond has many conservation areas and its own supplementary design guidance; roof extensions and front-facing changes need planning permission in most of the town. Semis outside the conservation areas in North Sheen and parts of Kew usually proceed under permitted development for lofts and rear extensions.

Conservation areas and Article 4 directions in Richmond

Richmond upon Thames has 72 conservation areas. Richmond Hill (designated 14 January 1969 and extended in 1975, 1977 and 2000) runs from the town up to the Terrace and the Park — cottages, almshouses, grand terraces and substantial residences in stock brick under slate. Richmond Green, Richmond Riverside, Kew and Sheen Road are the others we work in most. Article 4 directions cover a long list of streets inside the Richmond conservation areas (Bellevue Road, Glebe Road, Hillersdon Road, Laurel Road, Ranelagh Avenue, The Crescent and The Vineyard among them) as well as parts of Kew, Sheen Road and Richmond Riverside, removing permitted development for extensions and additions, new doors and windows, painting or rendering brickwork, removing chimneys and paving front gardens or replacing boundary walls. Outside those streets, front-facing changes remain permitted development but roof extensions, side extensions and two-storey rear extensions in a conservation area need planning permission (a single-storey rear extension within the national 3 m or 4 m limit is still permitted development); the inter-war semis of North Sheen and parts of Kew outside the boundaries take lofts and rear extensions on a Lawful Development Certificate.

The rules Richmond applies

The Richmond Local Plan 2024–2039 was adopted on 7 October 2025. The council’s House Extensions and External Alterations SPD (June 2015) sets the numbers officers have used: single-storey rear extensions of 3 m on a terrace, 3.5 m on a semi and 4 m on a detached house; Victorian infill extensions with eaves no higher than 2.2 m; two-storey rear extensions no more than half the width of the original house; side extensions set back at least 1 m behind the front and 1 m from the side boundary; dormers below the ridge leaving a significant area of the existing roof; and 40 m² of garden retained for a two-bedroom house or 70 m² for three or more bedrooms. The SPD applies the BRE 25-degree and 45-degree daylight tests, and we design to the 45-degree line as standard. Basements are ruled out altogether in the functional flood plain (zone 3b), and the council discourages excavation under more than half the front garden.

Fees and timescales

A householder application costs £548 (from April 2026, plus the Planning Portal charge) with an eight-week decision period. Richmond’s pre-application advice (from 26 June 2026) is £190 for a written householder response, or £660 with a site visit for a listed building, answered within 20 working days. Party wall notices run alongside planning: two months’ notice for works to a shared wall, one month for excavations within 3 m or 6 m of a neighbour’s foundations.

Building control

Building control is the shared Richmond and Wandsworth service. We use the council inspector on every project and book each inspection from foundations to completion, handing you the completion certificate at the end of the job.

Anderson's advice: talk to your neighbours before the notices go out

Semi-detached hip-to-gable plus rear dormer combinations almost always fall under permitted development, but neighbours often object informally. A conversation over the fence before the party wall notice lands avoids most of it.

What our clients say

“The Lccl construction team built my extension with a quick and clean service, they worked non stop through the winter weather.. I would highly recommend this company!”

— Chris Dunn, Google Reviews

As LABC Building Excellence Award winners in 2024 (Best Residential Extension in London) and 2026 (Best Conversion or Alteration to an Existing Home, Weech Road NW6), every project is delivered by one team of architects, structural engineers, project managers and builders. Workmanship is guaranteed for 12 months from practical completion, with a 10-year LABC structural warranty.

Nearby areas

Richmond is part of our South West London guide. Nearby areas: Fulham, Clapham, Putney & Wandsworth, Wimbledon.

To book a free consultation call LCCL Construction on 020 8037 7332 or get an instant estimate online. Get an instant estimate or book a free consultation.

One team, one contract, one point of contact — from first sketch to handover.