Extensions / Conversions in B20 (52)

Planning a loft conversion, garage makeover or full house extension in B20? 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 B20

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What to expect from hiring an extension or conversion builder in B20

Our checked tradespeople in B20 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 B20

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

Extensions:

£30700 on average, with prices typically starting at £19641 up to £47467.

Loft conversions:

£35371 on average, with prices typically starting at £23394 up to £53104.

Garage conversions:

£10253 on average, with prices typically starting at £7292 up to £14444.

Conservatory roof conversions:

£7742 on average, with prices typically starting at £5684 up to £10499.

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 B20: 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 B20

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 B20? Enter your postcode or post a job to find emergency services in your area.

Find the right extension or conversion specialist in B20

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