Frinton-on-Sea, Essex
Semi-detached rear extension in Frinton-on-Sea
Single or two-storey extensions for semi-detached houses, with side access and one party wall. We design, get the approvals for and build rear extensions for semi-detached houses in Frinton-on-Sea and the surrounding area, with one contract from the first survey to building control sign-off.
We cover Frinton-on-Sea (CO13 and CO14) as part of our Essex work. Semi-detached houses are common across Essex, and their side access makes rear extensions quicker to build.
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 Frinton-on-Sea?
In Frinton-on-Sea, our guide for a semi-detached rear extension is £2,010–£3,290 per square metre including VAT for a standard specification. East of England prices run slightly above our West Midlands baseline; clay soils near trees are the main foundation variable.
| Size | Guide price inc VAT |
|---|---|
| 3 m wide × 4 m deep (12 m²) | £24,000–£39,500 |
| 4 m wide × 5 m deep (20 m²) | £40,500–£65,500 |
| 4 m wide × 6 m deep (24 m²) | £48,500–£79,000 |
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 Frinton-on-Sea?
Planning for a semi-detached rear extension in Frinton-on-Sea follows the English householder rules.
In England a single-storey rear extension can often be built under permitted development: up to 3 metres beyond the original rear wall of an attached house, or 4 metres on a detached house, no higher than 4 metres, with eaves no higher than 3 metres if any part is 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. At the first visit we measure what is there now and tell you which route fits: permitted development, prior approval or a planning application.
What are homes in Frinton-on-Sea like to extend?
Post-war semis and newer estates are typical of Frinton-on-Sea, and many have room for a full-width extension. Shrinkable clay is common in the East of England, so foundations near trees and hedges are designed to NHBC-style depth guidance.
How a semi-detached rear extension in Frinton-on-Sea comes together
Survey visit
We visit free of charge, measure up, check access, drainage and neighbours' extensions, and note what you want the room to do.
Design and guide price
Two or three layout options with a guide price for each, so you choose the design knowing what it costs.
Approvals
Permitted development check, prior approval or planning application, then Building Regulations drawings and structural calculations, plus party wall notices where they apply.
Fixed price and build
A written price for the agreed design, a start date and a named contact through the build, ending with the building control completion certificate.
Semi-detached rear extensions near Frinton-on-Sea
From Frinton-on-Sea, the nearest places we also cover are Walton-on-the-Naze (1.6 miles) and Clacton-on-Sea (4.7 miles).
- Semi-detached rear extension in Walton-on-the-Naze
- Semi-detached rear extension in Clacton-on-Sea
- Semi-detached rear extension in Harwich
- Semi-detached rear extension in Felixstowe
- Semi-detached rear extension in Colchester
Other work in Frinton-on-Sea:
FAQ
Semi-detached rear extension questions in Frinton-on-Sea
Do I need planning permission for a rear extension in Frinton-on-Sea?
Often not for a single-storey rear extension of up to 3 metres (4 metres on a detached house) under permitted development, or up to 6 or 8 metres with prior approval, unless the house is in a conservation area or its rights have been removed.
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.
Do I need a party wall agreement?
Usually with the attached neighbour, in England and Wales.
Will I need a structural engineer?
Yes for the beam over the new opening and usually the foundations; we arrange them and their calculations go to building control.
Can you match the brick or stone on my Frinton-on-Sea house?
We source the closest match and show you samples before ordering; reclaimed materials are often the best match on older houses.
What postcode areas do you cover around Frinton-on-Sea?
Including CO13 and CO14, and the surrounding Essex area.