Spelthorne Planning Guide
We have completed over 300 home extension and loft conversion projects across Spelthorne Borough since 2014.
Staines, Ashford, Shepperton, Sunbury and Stanwell — we work across all of them.
Spelthorne has historically been one of the more straightforward boroughs to work with. Officers are consistent and measured. If you follow the guidelines, there is no good reason for a refusal. But the rules have changed recently, and applications now require more supporting information than they did a year ago.
Here is what you need to know.
Areas we cover in Spelthorne
Staines-upon-Thames (TW18, TW19) — 86 projects
Ashford, Surrey (TW15) — 83 projects
Sunbury-on-Thames (TW16) — 79 projects. Our home base.
Shepperton (TW17) — 31 projects
Stanwell (TW19) — 21 projects
What has changed in Spelthorne
Spelthorne Borough Council adopted new planning requirements in 2025 and 2026. Every application now needs additional supporting document that were not required before. Submit without them and your application will be returned as invalid — before the planning process even begins.
Climate Change Checklist
Spelthorne adopted a Climate Change Supplementary Planning Document that covers all residential development, including extensions and conversions. You must demonstrate how your design addresses the guidance, and submit a completed checklist with every application. No checklist, no validation.
Sustainable Drainage
Every application must now show that the development will not increase surface water run-off from the site. Even adding a new roof over an extension counts. We include this information as standard in all our Spelthorne submissions.
Design Code Checklist
A Design Code Checklist must be submitted with all applications. It covers scale, massing and materials. Our team completes this accurately for every project.
We manage all of this as part of our planning service. You do not need to think about it — we handle it.
Permitted development in Spelthorne
Many extensions and loft conversions in Spelthorne can still be done under permitted development — without a formal planning application. Single storey rear extensions within the standard size limits, rear dormers and hip to gable conversions can often proceed this way.
Some areas of Spelthorne have conservation areas and flood zone designations that affect this. We always check your specific position at the pre-planning consultation. For free.
What our Spelthorne clients say…
“From start to finish we felt we were in safe hands with Fluent. Their work ethic was great and they offered solutions to our questions quickly. Nothing was ever an issue.”
Verified Checkatrade review, TW15
“Fluent were first class from start to finish. They took away the pain of dealing with the council. Communication was awesome, regular updates, right through to the day the plans were passed.”
Verified Checkatrade review, TW16
Frequently asked questions
Since 2025, every application needs a completed Climate Change Checklist, evidence on Sustainable Drainage, and a Design Code Checklist. Applications submitted without these are returned as invalid before registration.
Many single storey rear extensions, rear dormers and hip-to-gable conversions can still be done under permitted development, subject to size limits. Some areas have conservation area or flood zone designations that affect this, which we check at the free consultation.
Historically, no — Spelthorne’s officers have been consistent and measured, and a well-prepared application following the guidelines has a good chance of approval. The main change recently is the extra supporting documentation now required, not a shift in how applications are judged.
Yes, it applies even to modest single storey extensions. Every application must demonstrate that the development won’t increase surface water run-off from the site, and that the receiving drainage system can cope with it.
Ready to start?
Call us on 020 3865 4917 or 0800 043 8838. Free consultation, no pressure, honest advice.
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