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Head Office in London

352 Fulham Road, London, SW10 9UH, UK

Contact Us

Looking for a quality and affordable builder for your next project?

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Phone

075 40 842 113

Working Hours

We are happy to meet you during our working hours. Please make an appointment.

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    Head Office in London

    352 Fulham Road, London, SW10 9UH, UK

    Contact Us

    Looking for a quality and affordable builder for your next project?

    * Please Fill Required Fields *
    img

    Phone

    075 40 842 113

    Working Hours

    We are happy to meet you during our working hours. Please make an appointment.

    Basements Conversions

    Basement Conversions In London

    A basement conversion is one of the most effective ways to add high-value space to a London home. From additional living areas and guest suites to gyms, cinemas, and home offices, a professionally built basement can transform how your property is used while significantly increasing its value.

    We deliver high-quality basement conversions across London, managing complex structural works with care, precision, and clear communication from start to finish.

    What Is A Basement Conversion

    A basement conversion involves excavating or refurbishing space below ground level to create habitable rooms. This may include:

    • Lowering floor levels

    • Structural underpinning

    • Waterproofing and drainage

    • Full internal fit-out

    Basement projects require specialist knowledge, detailed planning, and a experienced construction team to ensure long-term performance and safety.

    Types Of Basement Conversions We Undertake

    Basement Excavations

    Excavating beneath an existing property to create entirely new living space, often extending beneath gardens or existing footprints.

    Existing Basement Refurbishments

    Upgrading underused or damp basements into modern, dry, comfortable living areas.

    Light Wells & Access Solutions

    Introducing natural light and improved access through light wells, staircases, and glazing.

    Our Basement Conversion Process

    Basement projects demand careful coordination and technical expertise.

    1. Initial Assessment – Feasibility, structure, access, and constraints

    2. Planning & Approvals – Liaison with engineers, surveyors, and building control

    3. Construction Phase – Excavation, structure, waterproofing, fit-out

    4. Completion & Certification – Testing, sign-off, and handover

    Safety, quality, and compliance are prioritised at every stage.

    The Question Everyones Been Waiting For... Basement Conversion Costs

    The reason the answer to this question is so sought after is because it is really hard to give an answer to this question. You know it will be expensive and that can cause a lot of stress as it is a big commitment that in the early stages of planning and deciding wether to build or not will not come with a cost sheet.

    Basement conversion costs vary depending on depth, access, and specification. 

    Typical starting costs:

    • Basement conversions: from £3,500-£5,000 per m²

    • Complex excavations: £5,000+ per m²

    Costs are influenced by:

    • Structural complexity

    • Waterproofing systems

    • Access and logistics

    • Internal finishes

    A detailed site assessment is essential before providing an accurate quotation.

    It is very important to outline a rough budget when you start and work with your architect to design something that will fit your budget while providing you the type of space you are after. 

    Before anyone can provide you with a accurate quote they will need to do a site visit and have all the architectural and structural plans. 

    Planning Permission & Regulations

    Most basement conversions require:

    • Building regulations approval

    • Structural engineering input

    • Party wall agreements (very common)

    Planning permission may be required for:

    • Significant excavations

    • Changes to external appearance

    • Properties in conservation areas

    We guide clients through all necessary approvals to ensure full compliance.

    Why Choose Us For Your Basement Conversion?

    • Experience with complex basement projects

    • Strong focus on structural integrity and waterproofing

    • Clear project management and communication

    • High standards of workmanship and safety

    Basement conversions are specialist projects — experience matters.

    Frequently Asked Questions

    How long does a basement conversion take?

    Most basement projects take 16–30 weeks, depending on complexity.

    Will a basement add value to my property?

    Yes. In London, high-quality basement space can add substantial value when designed and executed correctly.

    Start Building Your Basement Conversion

    If you’re considering a basement conversion, working with an experienced construction company from the outset makes all the difference.

    We’re happy to:

    • Discuss feasibility and budgets

    • Provide clear advice on planning and timescales

    • Arrange a site visit to assess your property

    • Provide a Quote if you have had the plans made already 

    Contact us today to discuss your home extension project and take the first step toward transforming your home.

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