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House Extension Clapham | Rear, Side Return & Two-Storey Extensions | Crown Architecture

Extension architects | London Borough of Lambeth planning specialists | 97% first-application success | Fixed fees from £1,500 | Call 07443804841

Crown Architecture designs and delivers house extensions across Clapham and the wider London Borough of Lambeth area. Whether you are planning a single-storey rear extension, a side return infill, a wraparound extension, or a two-storey addition, our architects produce designs that make the most of your property while complying with Lambeth Council’s planning policies and the character of Clapham’s housing stock.

We manage the full process from initial feasibility and concept design through to planning permission, Building Regulations approval, contractor procurement, and contract administration.

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Types of House Extension in Clapham

Single-Storey Rear Extension

The single-storey rear extension is the most popular type in Clapham. By extending into the rear garden, it creates a larger kitchen, an open-plan kitchen and dining space, or an additional reception room. Many single-storey rear extensions in Clapham qualify as permitted development under Class A, subject to depth limits from the GPDO.

Crown Architecture designs single-storey rear extensions that maximise natural light using roof lanterns, bifold or sliding doors, and clever positioning of glazing. The build cost for a 20 sq m single-storey rear extension in Clapham is typically £30,000-£45,000.

Side Return Extension

The large victorian and edwardian terraces and semis surrounding clapham common, stucco-fronted properties, and newer mansion blocks in Clapham frequently have an underused side alley running alongside the kitchen – the side return. Filling in this space with a glazed side return extension transforms the kitchen from a narrow galley into a wide, light-filled room that opens onto the garden. Side return extensions are transformative in the typical Victorian and Edwardian terrace found across Clapham.

Side return extensions are often permitted development in Clapham, though party wall notices are almost always required. The build cost is typically £25,000-£45,000.

Wraparound Extension

A wraparound extension combines a rear extension with a side return infill to create an L-shaped addition at ground floor level. The wraparound maximises the available footprint and creates an exceptionally large open-plan ground floor encompassing kitchen, dining area, and living space that opens fully onto the garden.

Wraparound extensions in Clapham typically require planning permission from Lambeth Council. Crown Architecture prepares planning applications that respond positively to the Council’s design guidance.

Two-Storey Extension

A two-storey extension adds space both at ground floor and first floor level, providing the most significant increase in accommodation. Typical two-storey extensions in Clapham add a new bedroom and bathroom at first-floor level above a new kitchen or reception room below. Two-storey extensions always require planning permission from Lambeth Council.

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Planning for House Extensions in Clapham

Lambeth Council assesses householder planning applications for extensions against the Council’s Local Plan, the London Plan, and the NPPF. Key planning considerations include:

• Impact on the host property and streetscape: Extensions must not materially harm the appearance of the host property or character of the surrounding street.
• Impact on neighbouring amenity: Lambeth Council assesses impact on adjacent properties in terms of daylight, sunlight, outlook, and privacy.
• Conservation areas: In designated conservation areas within Clapham, additional scrutiny applies to materials, scale, and design.
• Permitted development: Crown Architecture confirms your permitted development position before starting the design.

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Transport and Connectivity in Clapham

Clapham is served by Clapham Common, Clapham North, and Clapham South Underground stations (Northern line). Crown Architecture has worked with homeowners throughout Clapham and in the neighbouring areas of Brixton, Battersea, Wandsworth, Balham, Stockwell.

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What Our Clapham Clients Say

Crown Architecture designed our rear kitchen extension in Clapham and it is exactly what we wanted. They handled the planning with Lambeth Council and the Building Regulations from start to finish. The project completed on budget and on time.

We used Crown Architecture for a side return extension. The design was brilliant – they really understood how to make the most of the space while keeping the character of our Victorian terrace. Lambeth Council approved first time.

Excellent architects. They knew what would and would not get planning permission in our conservation area and designed the extension around those constraints. We are so pleased with the result.

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Frequently Asked Questions – House Extensions in Clapham

What types of house extension are possible in Clapham?

The most common house extension types in Clapham are single-storey rear extensions, side return extensions, wraparound extensions, and two-storey extensions. The most appropriate type depends on your property’s layout, the size of the garden, and Lambeth Council’s planning policies.

Do I need planning permission for a house extension in Clapham?

Many single-storey rear extensions in Clapham can be built under Permitted Development rights without a planning application. Under Class A, a single-storey rear extension of up to 4 m (for a semi-detached or terraced house) or 8 m (for a detached house) may be built as permitted development. Extensions in conservation areas always require planning permission.

How much does a house extension cost in Clapham?

House extension build costs in Clapham typically range from £1,500 to £2,500 per square metre. A 20 sq m single-storey rear extension therefore costs approximately £30,000-£50,000. Crown Architecture’s drawings enable competitive contractor pricing.

How long does a house extension take to build in Clapham?

A single-storey rear extension in Clapham typically takes 10-14 weeks on site. The full project timeline is 4-6 months for a permitted development extension and 6-9 months where planning permission from Lambeth Council is required.

Will I need to move out during a house extension in Clapham?

Most families remain in their home during a house extension in Clapham. The most disruptive phase is the connection of the new extension to the existing house. Experienced contractors manage this process to minimise disruption.

Does a house extension add value in Clapham?

Yes. A well-designed house extension adds value in Clapham by increasing floor area and improving the layout. Industry data suggests a single-storey rear extension adds 5-10% to a property’s value, while a kitchen extension opening onto the garden can add significantly more.

What is the Party Wall Act and does it apply to extensions in Clapham?

The Party Wall etc. Act 1996 requires homeowners in Clapham to serve notice on adjoining owners when building on or close to a party wall. A rear extension close to a shared boundary typically requires party wall notices. Crown Architecture advises on the party wall position during the design stage.

Can Crown Architecture project manage my extension in Clapham?

Yes. Crown Architecture offers contract administration services whereby our architects act as contract administrator during construction, issuing instructions, managing changes, and certifying payments. This service provides assurance that the extension is built to the designed specification.

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Related Pages

• Architect in Clapham
• Loft Conversion Clapham
• Architect in Brixton
• Architect in Battersea
• Architect in Wandsworth
• Architect in Balham

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Contact Crown Architecture for House Extensions in Clapham

Phone / WhatsApp: 07443804841
Email: info@crownarchitecture.co.uk
Address: 71-75 Shelton Street, London WC2H 9JQ