Extensions / Conversions in SW17 (252)

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  • Sponsored
    LMB Group Ltd Logo

    LMB Group Ltd

    9.68

    (207 reviews)

    Operates in SW17

    Services & skills
    Builder
    Extensions / Conversions
    Loft Conversions
    Call
  • Sponsored
    District Construction Ltd Logo

    District Construction Ltd

    (6 reviews)

    Operates in SW17

    Services & skills
    Builder
    Extensions / Conversions
    Garden Studios
    Basement / Cellar Conversions
    Period Property Restoration
    Call
  • London Construction 24/7

    9.93

    (31 reviews)

    Operates in SW17

    Services & skills
    Builder
    Extensions / Conversions
    Refurbishments
    Fire and Flood Renovation
    Concreting
    Call
  • LMB Group Ltd Logo

    LMB Group Ltd

    9.68

    (207 reviews)

    Operates in SW17

    Services & skills
    Builder
    Extensions / Conversions
    Loft Conversions
    Call
  • Tolworth Construction Surrey ltd Logo

    Tolworth Construction Surrey ltd

    9.95

    (7 reviews)

    Operates in SW17

    Services & skills
    Builder
    Extensions / Conversions
    Suspended Ceilings
    Garage Conversions
    Concrete Garages
    Call
  • Absolute Building Services Limited Logo

    Absolute Building Services Limited

    10.00

    (124 reviews)

    Operates in SW17

    Services & skills
    Builder
    Extensions / Conversions
    Loft Conversions
    Garage Conversions
    Partition Walls
    Call
  • RW Construction Logo

    RW Construction

    9.93

    (38 reviews)

    Operates in SW17

    Services & skills
    Builder
    Extensions / Conversions
    Concrete Garages
    Brick / Concrete Structural Repairs
    Garden Studios
    Call
  • Renova Prime Ltd Logo

    Renova Prime Ltd

    9.83

    (8 reviews)

    Operates in SW17

    Services & skills
    Builder
    Extensions / Conversions
    Car Ports
    Garden Studios
    Equestrian Stable
    Call
  • Connolly General Contractors Limited Logo

    Connolly General Contractors Limited

    Be the first to review

    Operates in SW17

    Services & skills
    Builder
    Extensions / Conversions
    Loft Conversions
    Basement / Cellar Conversions
    Emergency Builder Service
    Call
  • Platinum Homes Construction Ltd Logo

    Platinum Homes Construction Ltd

    10.00

    (13 reviews)

    Operates in SW17

    Services & skills
    Builder
    Extensions / Conversions
    New Builds
    Loft Conversions
    Basement / Cellar Conversions
    Call
  • A H Construction (Surrey) Ltd Logo

    A H Construction (Surrey) Ltd

    8.00

    (39 reviews)

    Operates in SW17

    Services & skills
    Builder
    Extensions / Conversions
    Garden Studios
    Garage Conversions
    Call
  • A2z Constructions & Heating Ltd Logo

    A2z Constructions & Heating Ltd

    9.73

    (44 reviews)

    Operates in SW17

    Services & skills
    Builder
    Extensions / Conversions
    Garage Conversions
    Wall Tie Replacements
    Foundations
    Call

Conversion and extension builders in SW17

Planning a loft conversion, garage makeover or full house extension in SW17? 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 SW17

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 SW17

Our checked tradespeople in SW17 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 SW17

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

Extensions:

£32709 on average, with prices typically starting at £20085 up to £52106.

Loft conversions:

£35928 on average, with prices typically starting at £23495 up to £54370.

Garage conversions:

£11307 on average, with prices typically starting at £7931 up to £16168.

Conservatory roof conversions:

£8088 on average, with prices typically starting at £5783 up to £11360.

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 SW17: 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 SW17

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 SW17? Enter your postcode or post a job to find emergency services in your area.

Find the right extension or conversion specialist in SW17

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


Looking for more tradespeople in SW17?

Find Checkatrade reviewed Tradespeople, get a quote today, discover related services in SW17 and check out our latest home improvement guides.