14 years of



Covering London and Hertfordshire, United kingdom. Type of house extension we design and build:

  • Single storey rear house extensions

  • Single storey side house extensions

  • Two storey house extensions

  • Wrap around house extensions

  • Side return house extensions

  • House extension builders

  • Based in Finchley, London N3 covering London and Hertfordshire areas

Get instant quote for your home extension, including architecture and construction

Type of home extensions we do including architecture and construction, get your instant design and build quote 

  • Rear house extension

    Design and build of rear house extensions in London and Hertfordshire.

  • Wrap a round house extension

    Design and build of wrap a round house extensions in London and Hertfordshire.

  • Side house extension

    Design and build of side house extensions in London and Hertfordshire.

  • Side return house extension

    Design and build of side return house extensions in London and Hertfordshire.

  • Side and rear house extension

    Design and build of side and rear house extensions in London and Hertfordshire.

East Finchley, London N2 House Extension Project

Architecture design and build of the house extension located in North London. 

Single storey Extensions, Double storey Extensions, Side and Rear Home Extensions.

House extensions builders London and Hertfordshire. Our experience has allowed us to simplify the process of design, home building - construction and management, which means all the services are in one place delivering results to highest standards and on time. We only have experienced people working with us and for us and each stages are broken down into smaller stages to ensure each stage is managed, regulated and complied with government standards and most important meeting our customers standards.

House Extension Planning Permission

Information about local planning permission guidelines on house extensions click here >

House Extension


How much will it cost me, what are the costs associated with the house extensions find out >

Type of House Extensions

What type of house extensions are there? Single Storey, Side Return find out more >

House Extension Value

What will house extension add to my property value, house extension value find out >

House Extensions Service Locations

What areas in London and Hertfordshire do we cover. Find out more click here >

Design and Build Process

House extensions design and build process, what are the stages of design build find out >

We are a certified, accredited and fully insured company delivering construction services across London, Hertfordshire, North London and North West London. The specific areas of our house extension building services would include in Barnet, Borehamwood, Elstree, Hadley Wood, Cockfosters, East Barnet, Bushey, Finchley, St Albans, Potters Bar, Brent, Hampstead, Westminister, Chelsea, Ealing and Enfield. We are fully complaint with government and industry standards.

We build all types of extensions to highest standards single story extensions, double story extensions, triple story extensions, side and rear extensions, kitchen extensions, front extensions, loft extensions, loft conversions, wraparound house extensions full refurbishments and much more.

Lccl Construction is a responsible house extensions builder delivering responsible construction services that our customers can rely on and to rest assure the peace of mind we warranty our work for 10 years. 

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More About Lccl Construction House Extension Services

Why are we London and Hertfordshire leading house extensions builders?

We have the experience, skills and credibility to build any type of house extension in London and Hertfordshire. We offer both design services of the house extensions and construction of the house extensions. Have a look at our Portfolio! We have a 10 year guarantee for peace of mind. Get your free no obligation quote today!

How Much will my House Extensions Cost in London and Hertfordshire?

The costs for house extensions in London and Hertfordshire start from £15,000. The costs can depend on many factors such as type of house that it is, size of the house, size of the extension or whether it is rear house extension, wraparound house extension, side house extension, side and rear house extension or two storey house extension. Get in touch with us and we can book a free consultation and produce a quote that is valid for 6 months.

Area covering and near by locations

Lccl construction, house extensions builders services covers across London, North London, North West London, East London, South London, West London, South West London, South East London, North East London, Central London, Essex and Hertfordshire. The specific areas of our house extensions services would include in Barnet, Borehamwood, Elstree, Hadley Wood, Cockfosters, East Barnet, Whetstone and Totteridge, North Finchley, Woodside Park, Hendon, Colindale, Watford, Bushey, Finchley, St Albans, Potters Bar, Brent, Hampstead, Westminister, Chelsea, Ealing, Edgware, East Finchley, Wood Green, Palmers Green, New Southgate, Bow, Southgate, Cockfosters, Oakwood, Radlett, Muswell Hill, Highgate, Stoke Newington, Forest Hill, Hackney, Stratford, Crouch End, Walthamstow, Harringay, Chigwell, Dulwich, Lewisham, Twickenham, Richmond, Westminster, Kensington, Broxbourne, Walthamstow, Harringay, Wembley, Islington, Eltham, Brent, Watford, Camden, Enfield and many more areas get in touch to confirm if we cover your area. We are fully complaint with government and industry standards. We cover 85 mile radius from our offices in Barnet, London and Borehamwood, London.

House extension builders locations for London, UK and Hertfordshire, UK that we cover for house extensions. If the area is not listed on the below locations, give us a call to check whether we cover your location, we cover all areas in London and Hertfordshire.

The loft conversions locations for London, United Kingdom:

house extension builders lewisham

house extension builders eltham

house extension builders clapham

house extension builders richmond

house extension builders twickneham

house extension builders wandsworth

house extension builders brent

house extension builders southgate

house extension builders totteridge 

house extension builders crouch end

house extension builders chalk farm

house extension builders dulwich

house extension builders rickmansworth

house extension builders camberwell

house extension builders kentish town

house extension builders stratford

house extension builders fulham

house extension builders battersea

house extension builders pimlico

house extension builders westminster

house extension builders high barnet 

house extension builders stanmore

The loft conversions locations for Hertfordshire, United Kingdom:

house extension builders hertfrodshire 

house extension builders borehamwood

house extension builders potters bar

house extension builders st albans

house extension builders radlett

house extension builders watford

house extension builders northaw

house extension builders cuffley

house extension builders goffs oak

house extension builders brookmans park

house extension builders cheshunt

You can dive right on in and get started or get to know us better

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What are the stages in architecture, examples of the drawings, about the type of loft conversions and house extension.

Get free advice

It does not matter at what stage you are in book with us a consultation call online it is quick and simple, free of charge.

Loft Conversions

What are the different types of loft conversions, costs associated and return on investment, locations we operate in. 

Get Inspired

Have you seen our portfolio? we would pretty much have any type of project you could wish for, get inspired follow the link.

House Extensions

Types of house extension, what do they cost, where we build house extensions, value of house extensions.

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Finchley, London Office Location:

3rd Floor, Hathway House, Popes Dr, Finchley, London N3 1QF

Alexander Anderson Architectural Design Services, London Office Location:

Lyttelton House, 2 Lyttelton Rd, London N2 0EF



020 8037 7332

Office Hours:

Monday to Saturday 8AM - 6PM

Sunday - Closed

Registered company England:

North London Loft Conversions Ltd. Trading as "Lccl Construction" Registration: 11713461

Accreditation, partnerships and planning:

Planning Portal
Lodon and Hertforshire Construction Awards

Lccl Construction. Specialist loft conversion company, house extension builders, architectural design and planning. Design and build construction company from start to finish including architecture, planning, building control, party walls, structural calculations, project management, construction and finishing.

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