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Basement Conversions in Watford (187)

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  • Sponsored
    H&K Construction Logo

    H&K Construction

    8.98

    (20 reviews)

    Operates in Watford

    Services & skills
    Builder
    Extensions / Conversions
    Loft Conversions
    Garage Conversions
    Foundations
    Call
  • JFL Building Ltd Logo

    JFL Building Ltd

    9.81

    (107 reviews)

    Operates in Watford

    Services & skills
    Builder
    Extensions / Conversions
    Cladding
    Workshop Design / Construction
    Refurbishments
    Call
  • TNK Construction Ltd Logo

    TNK Construction Ltd

    10.00

    (7 reviews)

    Operates in Watford

    Services & skills
    Builder
    Extensions / Conversions
    Sustainable Construction
    Demolition
    Stretched Ceilings
    Call
  • H&K Construction Logo

    H&K Construction

    8.98

    (20 reviews)

    Operates in Watford

    Services & skills
    Builder
    Extensions / Conversions
    Garage Conversions
    Emergency Builder Service
    Refurbishments
    Call
  • Jhand Construction Ltd

    9.92

    (35 reviews)

    Operates in Watford

    Services & skills
    Builder
    Extensions / Conversions
    Agricultural Building
    Fire and Flood Renovation
    Mastic Sealant
    Call
  • AJAZI CONSTRUCTION LTD Logo

    AJAZI CONSTRUCTION LTD

    10.00

    (50 reviews)

    Operates in Watford

    Suggested Services
    Home Extension Services
    £1,200 / m²
    Call
  • Flamur Hoxha Building & Refurbs Logo

    Flamur Hoxha Building & Refurbs

    9.83

    (51 reviews)

    Operates in Watford

    Services & skills
    Builder
    Extensions / Conversions
    Garden Studios
    Fire and Flood Renovation
    Core Drilling
    Call
  • AMT Construction Logo

    AMT Construction

    9.81

    (17 reviews)

    Operates in Watford

    Services & skills
    Builder
    Extensions / Conversions
    Basement / Cellar Conversions
    New Builds
    Heritage Property Specialist
    Call
  • Bateman Builders

    10.00

    (95 reviews)

    Operates in Watford

    Services & skills
    Builder
    Extensions / Conversions
    Partition Walls
    Concreting
    Insurance Claim Specialist
    Call
  • Svv Smart Construction Limited Logo

    Svv Smart Construction Limited

    8.71

    (38 reviews)

    Operates in Watford

    Services & skills
    Builder
    Extensions / Conversions
    General Building
    Foundations
    Loft Conversions
    Call
  • G&V London Construction Ltd Logo

    G&V London Construction Ltd

    10.00

    (21 reviews)

    Operates in Watford

    Services & skills
    Builder
    Extensions / Conversions
    Green Oak Framing
    Stretched Ceilings
    General Building
    Call
  • Z & S Construction Logo

    Z & S Construction

    10.00

    (61 reviews)

    Operates in Watford

    Services & skills
    Builder
    Extensions / Conversions
    Demolition
    Garage Conversions
    Loft Conversions
    Call

Conversion and extension builders in Watford

Planning a loft conversion, garage makeover or full house extension in Watford? You’re in the right place. Whether you’re adding space for a growing family, upgrading your layout or increasing your home’s value, we can help you find the right tradesperson for the job.

Find extension and conversion builders in Watford

Every builder on Checkatrade passes up to 12 checks before they appear in your search. You can read verified reviews, compare services, and even post your job to get quotes straight to your inbox, all in a few clicks. That’s how we help homeowners like you get a job done right.

What to expect from hiring an extension or conversion builder in Watford

Our checked tradespeople in Watford cover a wide range of projects, including:

  • Single or double-storey house extensions

  • Kitchen and diner extensions

  • Loft, attic, garage or basement conversions

  • Garden room extensions

  • Utility room extensions

  • Over-garage extensions and side returns

Extension and conversion build costs in Watford

Costs of extensions and conversions vary depending on size, structure and spec, but here's a rough guide:

Extensions:

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Loft conversions:

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Garage conversions:

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Conservatory roof conversions:

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Need help calculating costs? Use our Job Value Estimator Tool for a bespoke cost estimate.

What to check before you hire:

  • Are drawings or planning permissions needed?
  • Are they familiar with building regs?
  • Is the quote fixed or flexible?
  • Does it cover materials and project management?

Most builders will include prep, construction, electrics, plumbing and final finishes in their quote, but always double-check. Timelines range from a few weeks for simple jobs to several months for bigger builds.

Extension and conversion builders in Watford: Homeowners vs renters

Homeowners:

You’re in charge of the project. That means hiring the builder, securing permissions, and paying for the work. You may need:

  • Planning permission (especially for double-storey builds or changes near boundaries)

  • Drawings from an architect or structural engineer

  • Building regs approval

If you’re not sure where to start, speak to a local builder or post your job to get help with the process.

Renters:

You’ll usually need your landlord’s approval to make any big changes. In most cases, your landlord will be the one arranging and paying for structural changes like loft conversions or extensions. That said, it’s worth flagging ideas if you think they’ll improve the property, especially if it means longer tenancies or fewer repairs.

Emergency extension or conversion help in Watford

Extensions and conversions are big projects, but sometimes, things go wrong and need sorting fast. Common urgent issues include:

  • Leaks in newly converted lofts

  • Structural cracks or shifting

  • Faulty electrics or plumbing in newly added rooms

  • Incomplete work by previous builders

Facing an emergency in Watford? Enter your postcode or post a job to find emergency services in your area.

Find the right extension or conversion specialist in Watford

Looking for a builder to help with:

  • Rear house extensions
  • Kitchen extensions
  • Garage conversions
  • Loft or attic conversions
  • Garden room builds
  • Basement or cellar conversions
  • Conservatory roof upgrades
  • Utility or porch extensions

Start your search now


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