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    Glazed rear extension with open bifold doors onto a London garden

    Home Extensions

    Home Extensions in London & the South East

    Ready to build your home extension? Already have architectural drawings or planning approval? Get a construction quotation from LINX Design and Build, for rear, side return, wraparound and double-storey extensions across London & the South East.

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    Since 2017 800+ projects Workmanship guarantee

    Award-winning · FMB & TrustMark approved · Fully insured

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    Takes 30 seconds · Director call-back · No obligation

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    Real Projects

    Watch Real Projects Come Together

    See the work behind the finish — on-site, walkthroughs and start to handover.

    4.9★ from 500+ reviews on Google, Houzz, Reviews.io & TrustATrader

    Colwith Road · BuildInside the build
    South Croxted Road · SE21Infill kitchen extension — from the air and on site
    Vitali Close · SW15Rear Extension — Vitali Close
    Wallington, Surrey · SM6Rear extension & full renovation
    Sunbury · BuildOn-site with the homeowner
    Woodend Road · E17Woodend Road — Extension complete
    Loft ConversionEdward — Loft conversion
    Real projectOn-site with LINX
    Real projectKitchen extension & porch — completed project
    Real projectRear extension & bathroom — completed project
    East HorsleyHome ExtensionView
    Arlington SquareFull RenovationView
    SudbourneLoft ConversionView
    Architectural walk-throughView

    Client Stories

    Hear From Our Clients

    Real projects, real results — straight from the people we've worked with.

    South Croxted Road · SE21Infill kitchen extension walkthrough
    Sunbury · CompleteFinished extension walkthrough
    Colwith Road · HammersmithRear extension & renovation

    How your project works

    Six clear stages, from first enquiry to completion — whether we design and build, or build from your drawings.

    For clients who need the whole project managed: design, planning, building regulations and construction, from initial enquiry through to completion.

    1. Step 1: Initial Consultation & Feasibility

      Timeline: 1–3 days

      Initial consultation to discuss requirements, ideas and budget.

    2. Step 2: Architectural Design & Drawings

      Timeline: 1–4 weeks

      Architectural drawings and proposed layouts.

    3. Step 3: Planning Permission

      Timeline: 6–12 weeks (estimated)

      Planning application preparation and submission.

    4. Step 4: Structural Engineering & Building Regulations

      Timeline: 1–3 weeks, depending on complexity

      Structural calculations and drawings.

    5. Step 5: Contract & Building Works

      Timeline: Typically 4–20+ weeks, depending on project type

      Begin construction and manage all building works.

    6. Step 6: Completion & Handover

      Final client walkthrough and handover.

    All timelines are indicative. Your project-specific schedule is confirmed before construction.

    Starting from
    £60,000
    Typical duration
    12–16 weeks
    Projects delivered
    800+
    Guaranteed in writing
    Fixed price

    Six steps from first call to handover — see how your project works.

    Recent projects

    All projects
    Isleworth TW7 Extension & Porch by LINX Design and Build
    Home Extension

    01 / 13

    Isleworth TW7Extension & Porch

    Fixed Price Guarantee

    Extension Pricing Made Simple

    No hidden costs. No surprises. Get a fixed quote that covers everything from design to completion.

    10% on Signing • Milestone Payments

    Most popular

    Single-Storey Rear

    From £60,000

    The classic rear extension – open up your kitchen or living space into the garden.

    Includes

    • Full foundations & groundworks
    • Structural walls & steelwork
    • Flat or pitched roof
    • Bi-fold or sliding doors
    • Electrical & plumbing
    • Plastering & decoration
    • Building Control approval
    Get Quote

    Wrap-Around Extension

    From £65,000

    Maximise your ground floor with rear and side extensions combined.

    Includes

    • L-shaped or full wrap design
    • Multiple steel beams (RSJs)
    • Premium glazing options
    • Internal reconfiguration
    • Full M&E installations
    • Seamless match to existing
    • Project management included
    Get Quote

    Double-Storey Extension

    From £85,000

    Add significant space on both floors – bedrooms above, living below.

    Includes

    • Full structural design
    • Ground & first floor build
    • New staircase alterations
    • Multiple rooms created
    • Full electrical rewire
    • Central heating extension
    • Workmanship guarantee
    Get Quote

    What's Always Included

    • Dedicated project manager
    • Health & safety compliance
    • Building Control coordination
    • Structural engineer sign-off
    • Site management
    • Workmanship guarantee
    • Established 2017
    • Fixed Price Guarantee
    • Workmanship Guarantee
    • Fully Insured

    Full Transparency

    Extensions – What's Included

    Applies to rear, side, wrap-around, L-shaped, double-storey and first-floor extensions.

    Typically Includes

    • Site setup, protection & health & safety
    • Foundations, groundworks & drainage
    • Structural works (walls, floors, roof structure)
    • Steel beams (RSJs) where required
    • External walls, brickwork or render to match existing
    • Roofing (flat or pitched, insulation, waterproofing)
    • Windows, doors & glazing
    • Internal studwork & insulation
    • Electrical installation (lighting, sockets)
    • Plumbing & heating connections
    • W/C installation (if required)
    • Bathroom installation (if included in scope)
    • Kitchen installation (if included in scope)
    • Plastering, flooring & decoration
    • Building Control inspections & sign-off
    • Full project management

    Does Not Include (unless specified)

    • Kitchen supply
    • Bathroom fittings
    • Specialist finishes or smart systems
    • Planning fees (if applicable)

    How You Pay

    Milestone Payment Plan

    No large upfront deposits. You pay in stages as work is completed, inspected and approved by your project manager.

    Calculate Your Payment Plan

    Adjust the slider to see how milestone payments break down for your project budget.

    Your Project Value

    £60,000
    £30,000£10,000,000

    Illustrative Example — The amounts shown below are based on a £60,000 project for illustration purposes only. Your actual payment schedule will be tailored to your specific project scope, specifications and agreed contract value. Milestone percentages remain consistent across all project sizes.

    1

    Contract Signing

    10%

    £6,000

    Contract signed, project scheduled & materials ordered

    Upon signed contract & project commencement date agreed
    First Payment
    2

    Foundations & Groundworks

    15%

    £9,000

    Excavation, foundations poured, drainage & damp proofing

    Upon foundation inspection passed by Building Control
    3

    Superstructure

    15%

    £9,000

    Walls built, steel beams installed & roof structure erected

    Upon walls at plate level & roof structure complete
    4

    Weathertight Shell

    15%

    £9,000

    Roof tiled, windows & doors fitted, property sealed

    Upon building being fully sealed & weathertight
    5

    First Fix

    15%

    £9,000

    Electrics, plumbing, heating & insulation installed

    Upon first fix M&E inspection signed off
    6

    Plastering & Boarding

    10%

    £6,000

    All walls & ceilings boarded, skimmed & dried

    Upon plastering complete & ready for second fix
    7

    Second Fix & Finishes

    15%

    £9,000

    Kitchen fitted, flooring laid, painting & decoration

    Upon snagging walkthrough with client
    8

    Completion & Handover

    5%

    £3,000

    Final snagging resolved, Building Control sign-off & keys handed over

    Upon completion certificate issued & client sign-off
    Discuss Your Payment Plan

    No obligation • Free consultation • Reply within 24 hours

    Finance options

    Build now. Spread the cost.

    Planning an extension? LINX can help you explore a range of finance routes, from spreading smaller payments through Klarna or PayPal to secured and bridging finance on larger works — subject to eligibility, affordability, lender criteria and approval.

    • Klarna
    • PayPal
    • Secured / second-charge
    • Bridging finance

    LINX Living Ltd is not authorised or regulated by the Financial Conduct Authority and acts as an introducer only. We are not the lender, we do not give financial advice, and we do not make or influence any lending decision. This is not an offer of finance and no approval is guaranteed. Where finance is provided by Klarna, PayPal or another lender, that provider’s own eligibility checks, terms and charges apply and missing payments may affect your credit file. Your property may be at risk if you fail to keep up repayments on a loan secured against it. Full finance information.

    from 500+ reviews
    4.9★
    workmanship
    Guaranteed
    projects completed
    800+
    London & the South East
    Est. 2017
    Award winning on HouzzBest of Houzz 2026 — ServiceBest of Houzz 2024 — ServiceBest of Houzz 2019 — ServiceBest of Houzz 2018 — ServiceHouzz RecommendedHouzz 100 Saves

    What we do

    One team. Every discipline.

    From the first sketch to the final handover: architecture, residential, commercial and new builds, delivered under one accountable roof.

    Looking for something specific?

    Explore all services

    4.9★ from 500+ reviews

    What our clients say.

    Customer Reviews

    Read what our customers say about our services

    • ★★★★★

      Our new loft conversion has us utterly thrilled! Our underused attic was turned by the Linx team into a lovely, light-filled, and cosy area that is ideal for living, working, and unwinding. The workmanship, craftsmanship, and attention to detail were superb. Everything fits in well with the rest of our house. Excellent outcomes and service. Strongly suggested!

      Jordan R. · Reviews.io ·

    • ★★★★★

      Our expectations were surpassed by LINX Design's outstanding office and warehouse development. The crew showed exceptional professionalism, technical know-how, and attention to detail from the first free site evaluation to the last handover. We had total confidence from the start thanks to the fixed-price quote, and the job was handled effectively all along the way. Their seamless integration of design, fabrication, and installation services produced a contemporary, useful, and aesthetically pleasing workstation. Every element of the construction demonstrates the high calibre of workmanship, and the warranty added even more assurance. We are thrilled with the completed building and would heartily suggest LINX Design for any commercial or industrial building project.

      Alexander O. · Reviews.io ·

    • ★★★★★

      The phase of architectural design and drawings was overseen with remarkable skill and meticulousness. After conducting a thorough property survey, excellent architectural drawings and suggested layouts were created. The team meticulously took into account every comment, producing design changes quickly and guaranteeing a smooth approval process all along the way. Thanks, Linx Owner Gary Pal and your all Guys!!!

      Michael B. · Reviews.io ·

    • ★★★★★

      LINX Design and Build completed our loft conversion to an exceptional standard and delivered everything on schedule. The team provided clear daily updates, maintained a clean and safe worksite, and demonstrated outstanding craftsmanship throughout the project. Our dedicated project manager ensured a smooth, stress-free experience. We highly recommend their renovation services.

      Robert P. · Reviews.io ·

    • ★★★★★

      Outstanding service from LINX Design and Build. From the initial consultation to the final handover, the team was professional, knowledgeable, and hardworking. Their commitment to quality, innovation, and customer satisfaction was evident throughout the project. Every aspect of the build was completed with care and precision, resulting in a finished home that exceeded our expectations. We highly recommend LINX Design and Build for anyone looking for a trustworthy and experienced building company.

      Joseph P. · Reviews.io ·

    • ★★★★★

      We are extremely happy with our kitchen infill extension and renovation. The team was professional, friendly, and reliable throughout. Their workmanship and attention to detail were excellent, transforming our space beautifully. Highly recommended for quality, service, and outstanding results!

      James K. · Reviews.io ·

    Our Trusted Partners

    AUTHORISED SUPPLIERS

    CHAS
    Constructionline
    NICEIC
    Federation of Master Builders
    TrustMark
    SafeContractor
    Gas Safe Register
    SMAS Worksafe
    IWA – Independent Warranty
    HomePro
    Freedom Homes Architects
    Extension Plans
    Trusted Partner
    RAMs

    Our team

    The People Behind LINX

    An in-house team delivering every project from first sketch to final handover — backed by 60+ tradesmen on site.

    • Gary Pal, Managing Director at LINX Design and Build

      Gary Pal

      Managing Director

    • Cristian Ghertan, Construction Director at LINX Design and Build

      Cristian Ghertan

      Construction Director

    • Ryan Anthony, Project Manager at LINX Design and Build

      Ryan Anthony

      Project Manager

    • Atul Singh, Project Manager at LINX Design and Build

      Atul Singh

      Project Manager

    • Steve McDermott, Project Consultant at LINX Design and Build

      Steve McDermott

      Project Consultant

    • Alexis Urbina, Business Development Manager at LINX Design and Build

      Alexis Urbina

      Business Development Manager

    • Vishal Gajjar, Business Growth Strategist at LINX Design and Build

      Vishal Gajjar

      Business Growth Strategist

    • Thomas Phillips, Head of Design at LINX Design and Build

      Thomas Phillips

      Head of Design

    • Manisha Silwal, Customer Service at LINX Design and Build

      Manisha Silwal

      Customer Service

    • Joseph Gomes, Tech / IT at LINX Design and Build

      Joseph Gomes

      Tech / IT

    FAQs

    Questions about home extensions

    Ask us something else

    A single-storey rear extension starts from £60,000, a side return from £52,000 and a side extension from £55,000. Wrap-around and L-shaped extensions start from £65,000, over-garage from £75,000, first-floor from £80,000 and double-storey from £85,000.