Read Christian's full reviewWe spoke to a number of companies about designing and building our loft extension, one of whom wanted to put a box on the back and another said the existing room configuration would make it too hard to do! Leigh and Sarah had great vision for what could be achieved and worked with the architect to…

Areas covered
Loft conversions, extensions and renovations in Spelthorne
Surrey Build Group designs and builds loft conversions, extensions and alterations across Spelthorne, including Staines-upon-Thames, Ashford, Shepperton, Sunbury-on-Thames and Stanwell. Our in house architects, structural engineers and builders deliver every stage, with your build cost locked in from the start.
Local knowledge
Building in Spelthorne
Spelthorne moved from Middlesex into Surrey in 1965, which is why many local addresses still read Middlesex. The borough follows the Thames from Staines-upon-Thames, where the River Colne joins it beside the granite Staines Bridge of 1832, down to Sunbury-on-Thames. It is home to Shepperton Studios, and the Queen Mary and King George VI reservoirs shape the landscape around Ashford and Stanwell.
Much of the housing is Victorian terraces and interwar and postwar semis, which are ideal for dormer and hip to gable lofts and single storey rear extensions. Riverside homes in Staines, Shepperton and Sunbury bring their own considerations, including flood risk, which we factor into the design from the start.
What we do
Our services in Spelthorne
Every service is designed, engineered and built by our own team for homes across Spelthorne.
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Loft conversions in Spelthorne
Velux, dormer, hip to gable and mansard lofts, plus bungalows expanded upwards, designed and engineered in house.
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Extensions in Spelthorne
Single and double storey, side return and wraparound extensions, with open plan kitchens built around steels.
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Design and build in Spelthorne
In house architects and structural engineers working with our own build team, under one contract.
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Structural alterations in Spelthorne
Knock throughs, steel beams, chimney breast removal and new openings, designed by our structural engineer.
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Garage conversions in Spelthorne
Integral and attached garage conversions into offices, bedrooms and family rooms, plus detached garage renovations.
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Project management in Spelthorne
A dedicated site crew, project manager and project coordinator running your build, with daily updates in your client portal.
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Under one roof
Why Spelthorne homeowners choose us
A streamlined, comprehensive service supporting you through the whole journey, from concept to completion. The people who design your home work beside the people who build it, so nothing gets lost between consultants and contractors.
Read Nigel's full reviewWe are delighted with our new loft space. From our enquiry right through to completion of the project, Leigh and the team have been responsive and supportive, delivering a light and bright bedroom and bathroom which has exceeded our expectations. Leigh's design vision coupled with site manager…
Read Emma's full reviewWe recently had a loft conversion and large extension completed by Surrey Build Group, and I honestly couldn’t recommend them more highly. From the very first visit, Leigh was incredibly knowledgeable. He took the time to clearly explain what was possible in terms of the build, as well as what…
Our work
Recent projects in Spelthorne
Open larger photoAlbert Road, Ashford TW15
Open larger photoAlbert Road, Ashford TW15
Open larger photoAlbert Road, Ashford TW15
Questions
Building in Spelthorne: common questions
Do you cover Spelthorne and the surrounding area?
Yes. We work across Spelthorne, including Staines-upon-Thames, Sunbury-on-Thames, Ashford, Shepperton, Stanwell, covering the TW15, TW16, TW17, TW18, TW19 postcodes, and we serve homeowners across all Surrey postcodes.
Do I need planning permission for a loft conversion or extension in Spelthorne?
Many loft conversions and single storey rear extensions fall under permitted development, but conservation areas, flats and larger projects need planning permission. Applications for Spelthorne homes are decided by the local planning authority, currently Spelthorne Borough Council, and we prepare and submit everything on your behalf.
How much does a loft conversion or extension cost in Spelthorne?
We price every project after a survey, because the size, structure and finish of each home is different. When you appoint us, your agreed build cost is locked in, protecting you from unexpected costs during the build.
Nearby areas we cover

Project Kick Start Meeting
Ready to talk about your project?
Book your Project Kick Start Meeting. We will talk through your plans, explain what is possible and follow up with a design and a fixed build price.
- In house architects and structural engineers
- Your build cost locked in when you appoint us
- A dedicated site crew, project manager and project co-ordinator
Prefer to talk? Call 0203 603 9777 or email hello@surreybuild.co.uk.
