Romford, Greater London
Semi-detached rear extension in Romford
We plan and build rear extensions for semi-detached houses for homeowners in Romford. Single or two-storey extensions for semi-detached houses, with side access and one party wall. Start with a free site visit, then a written price once the design is agreed.
Romford sits in Greater London, with postcode districts including RM2, RM3, RM5 and RM7. Where a Romford semi already has a small lean-to at the back, we usually replace it rather than extend it.
Book a free site visit
Tell us about the house and we'll call to arrange a free, no-obligation visit.
How much does a semi-detached rear extension cost in Romford?
Guide prices for a semi-detached rear extension in Romford start from our London rate of £2,470–£4,030 per square metre, including VAT. London prices sit at the top of our range because of labour rates, access through the house, parking suspensions and skip licences.
| Size | Guide price inc VAT |
|---|---|
| 3 m wide × 4 m deep (12 m²) | £29,500–£48,500 |
| 4 m wide × 5 m deep (20 m²) | £49,500–£80,500 |
| 4 m wide × 6 m deep (24 m²) | £59,500–£96,500 |
Your written price follows a measured survey and an agreed design, so it reflects your house, not an average.
Do you need planning permission for a semi-detached rear extension in Romford?
Here is how the rules in England apply to a semi-detached rear extension in Romford.
English permitted development (Class A) allows a single-storey rear extension of 3 metres on a terraced or semi-detached house and 4 metres on a detached one, measured from the original house, with a maximum height of 4 metres and eaves of no more than 3 metres within 2 metres of a boundary.
England's rules allow a rear extension of more than one storey without an application only when it is no deeper than 3 metres and at least 7 metres from the boundary opposite the rear wall, and never on designated land. Most two-storey schemes need householder planning permission.
If 3 or 4 metres is not enough, England's prior approval route allows 6 metres on a terraced or semi-detached house and 8 metres on a detached house for a single-storey rear extension. Neighbours are consulted, the council decides within 42 days, and the fee is £249, rising to £310 from 8 December 2026.
Conservation areas, National Parks, National Landscapes and the Broads restrict permitted development, and listed buildings always need listed building consent. Before any drawing we look up the property's history with the council, because earlier extensions and removed rights change the answer.
What are homes in Romford like to extend?
Romford is mostly 1930s semis, short terraces and post-war houses, so full-width single-storey and two-storey rear extensions are realistic on many plots. Some later estates had permitted development rights removed by condition, so we check the planning history first.
How a semi-detached rear extension in Romford comes together
Look round and measure
A free visit to see the back of the house, measure it, check the drains and boundaries and hear what you need.
Options and costs
We draw layout options and price each one, so the budget shapes the design rather than surprising you later.
Approvals
Permitted development check, prior approval or planning application, then Building Regulations drawings and structural calculations, plus party wall notices where they apply.
Build and sign-off
We build to the approved drawings with regular updates, then hand over the building control completion certificate and any guarantees from suppliers.
Semi-detached rear extensions near Romford
From Romford, the nearest places we also cover are Hornchurch (1.8 miles) and Collier Row (1.9 miles).
- Semi-detached rear extension in Hornchurch
- Semi-detached rear extension in Collier Row
- Semi-detached rear extension in Dagenham
- Semi-detached rear extension in Emerson Park
- Semi-detached rear extension in Elm Park
Other work in Romford:
FAQ
Semi-detached rear extension questions in Romford
How long does a rear extension take to build in Romford?
Most single-storey rear extensions take 10 to 16 weeks on site and two-storey extensions 16 to 26 weeks, after design and approvals.
Can you match the brick or stone on my Romford house?
We source the closest match and show you samples before ordering; reclaimed materials are often the best match on older houses.
What if my neighbour has already extended?
That can make a matching depth easier to justify. We measure theirs at the survey.
Who will build my extension?
Vetted building teams working under contract to us. Your contract is with S&K Property Investments and Improvement Ltd for the design and the build.
How much does a semi-detached rear extension cost in Romford?
As a guide, £2,470–£4,030 per square metre including VAT for a standard specification. For example, 3 m wide × 4 m deep (12 m²): about £29,500–£48,500 at that rate. Your written price follows the survey.
What postcode areas do you cover around Romford?
Including RM2, RM3, RM5, RM7, RM11 and RM12, and the surrounding Greater London area.