Extensions in Dagenham: design, planning and build
From a small utility to a two-storey addition, we take on house extensions throughout Dagenham, starting with a free visit and a planning check.
- Postcode districtsRM7, RM8, RM9, RM10, RM12, RM13
- Price regionLondon (×1.3)
- Planning rulesEngland
- Site visitFree, no obligation
Dagenham extension prices at a glance
Use these Dagenham guide prices to sense-check a budget; the guide-price tool narrows them to your own size, and the site visit turns them into a written figure.
| Extension type | Example size | Standard spec (inc VAT) |
|---|---|---|
| Kitchen extensions | 20 m² | £54,500 – £69,000 |
| Wraparound extensions | 25 m² | £74,500 – £94,500 |
| Conservatory replacement extensions | 14 m² | £39,000 – £50,500 |
| Single-storey rear extensions | 20 m² | £53,000 – £68,000 |
| Double-storey extensions | 32 m² | £74,500 – £98,000 |
Dagenham and surrounding towns
We cover Dagenham and the postcode districts RM7, RM8, RM9, RM10, RM12, RM13. The same team covers Becontree (2 miles), Romford (2 miles), Hornchurch (2 miles), Barking (4 miles), Thamesmead (4 miles), all within easy reach. For homes towards Essex, South Ockendon is around 6 miles away.
Do extensions in Dagenham need planning permission?
In England a single-storey rear extension can usually go up to 3 m beyond the original rear wall of a semi-detached or terraced house, or 4 m on a detached house, without a planning application, provided it is no more than 4 m high, keeps eaves to 3 m within 2 m of a boundary and, with other buildings, covers no more than half the land around the original house. The larger home extension prior approval scheme raises those depths to 6 m and 8 m, with neighbours notified and a 42-day decision.
In England a two-storey rear extension is permitted development only if it projects no more than 3 m from the original rear wall, sits at least 7 m from the rear boundary, matches the roof pitch and uses obscure, non-opening side windows upstairs. Most two-storey extensions therefore go through a householder planning application, which costs £548 from 1 April 2026 and normally takes about 8 weeks.
In a conservation area, national park, National Landscape, the Broads or a World Heritage Site the permitted development limits are tighter (no side or two-storey extensions without an application). Listed homes need listed building consent, and if permitted development rights have been removed, any extension needs an application.
Building regulations approval is separate from planning. In England you can use the council's building control team or a registered building control approver; a full plans application gets the drawings checked before work starts, and the inspector signs the work off with a completion certificate.
Applications are decided by the local planning authority (your district, borough or unitary council).
What works best for Dagenham houses?
In London, space is at a premium and gardens are often short, so side returns, wraparounds and carefully planned rear extensions tend to make the most of every metre.
For many houses here, side return extensions, glass box extensions or kitchen extensions gives the most useful space for the budget.
Extension types and starting prices
- Side extensions · from £28,500
- Pitched roof extensions · from £28,500
- Timber frame extensions · from £27,000
- Double-storey extensions · from £49,000
- Porch extensions · from £5,200
- Annexe extensions · from £71,500
- Side return extensions · from £23,000
- Building regulations for extensions · from £1,150
- Wraparound extensions · from £46,500
- Planning permission for extensions · from £450
- Orangery extensions · from £39,000
- Single-storey rear extensions · from £27,000
- Extension plans and drawings · from £1,550
- Bedroom extensions · from £33,500
- Extensions over a garage · from £31,000
- Bungalow extensions · from £34,000
- Glass box extensions · from £39,000
- Home office extensions · from £20,500
- Flat roof extensions · from £27,000
- Utility and boot room extensions · from £18,000
- Kitchen extensions · from £35,000
- Conservatory replacement extensions · from £26,000
Free site visit
It starts with a visit to your house to measure, check access and talk through ideas and budget.
Design and approvals
We draw the design, agree it with you and handle planning or permitted development checks and building regulations.
Fixed written price
With the design and specification agreed, you get a fixed written price and a start date.
Build and sign-off
Our team builds the extension, keeps you updated weekly and finishes with building control sign-off.
Questions about extensions in Dagenham
How much does an extension cost in Dagenham?
Using our London factor (×1.3), a standard-spec single-storey extension of 20 m² is a guide £53,000 to £68,000 including VAT, and a 32 m² two-storey extension £74,500 to £98,000. Your written price follows the survey.
Will my neighbours need to be told?
If you apply for planning or prior approval the council notifies them, and in England party wall notices may be needed for work near a shared boundary.
Do you handle building regulations?
Yes. We prepare the drawings and calculations, submit them and book inspections, ending with a completion certificate.
Do you cover all of Dagenham?
Yes, including the surrounding parts of Greater London. Site visits are free and there is no obligation.
Book a free site visit in Dagenham
We will measure up, check the planning position and give you honest guide figures.
- Free, no-obligation site visit
- Planning route checked before you spend on drawings
- Written price once the design is agreed
- Building control sign-off at the end
Prefer to talk? Call 0800 088 6341 or .
Book a free site visit
Tell us a little about the project and we will arrange a time.