Two-storey extensions in Brentwood
Everything for a two-storey extension in Brentwood, in one place: types, guide prices for the East of England, the approval rules in England and how to get started.
Brentwood at a glance
- Postcode districts
- CM13, CM14 and CM15
- Area
- Essex, England
- Price region
- East of England
- Nearest towns
- Harold Wood (3.6 miles), Emerson Park (4.5 miles), Billericay (4.9 miles), Upminster (5 miles)
- Distance to Southend-on-Sea
- about 18.5 miles
- Approvals
- Two-storey rear: up to 3 m deep and 7 m from the rear boundary under permitted development. Side, wraparound and front: planning permission.
Around Brentwood we also work in Harold Wood, Emerson Park and Billericay, and across the rest of Essex. Postcode districts in and near Brentwood: CM13, CM14 and CM15.
Extensions available in Brentwood
Two-storey rear extensions
For homes in Brentwood: typical guide from £57,500.
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Two-storey side extensions
Our East of England guide starts at £88,500 for this type.
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Two-storey wraparound extensions
Guide from £124,000 in Brentwood, including VAT.
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Part single, part two-storey extensions
Brentwood guide price from £74,000, Standard spec.
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Extensions over a garage
From £32,500 in Brentwood. Free visit to firm it up.
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First-floor extensions
Our East of England guide starts at £26,000 for this type.
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Two-storey extensions for semi-detached houses
From £57,500 in Brentwood. Free visit to firm it up.
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Two-storey extensions for detached houses
Design, approvals and build for Brentwood homes. Guide from £88,500.
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Kitchen extensions with bedrooms above
Guide from £57,500 (before kitchen units) in Brentwood, including VAT.
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Extra bedroom and en-suite extensions
Our East of England guide starts at £57,500 (plus en-suite) for this type.
Learn moreWhich type suits your house?
Which type suits your house in Brentwood depends mostly on where you have room. A deep garden points to a rear extension; space beside the house points to a side or over-garage extension; a house that already has a single-storey extension can often take a first floor on top.
Also available in Essex
- Two-storey front extensions
- Two-storey extensions for end-of-terrace houses
- Two-storey annexe extensions
- Garage conversions with a room above
- Two-storey extension plans and drawings
- Planning permission for two-storey extensions
- Structural engineering for two-storey extensions
- Building regulations for two-storey extensions
- Party wall notices for extensions
- Design and build two-storey extensions
Rules for Brentwood
Brentwood is in England. Two-storey rear: up to 3 m deep and 7 m from the rear boundary under permitted development. Side, wraparound and front: planning permission. Householder planning application: £548 (or £575 for applications made from 8 December 2026). Lawful development certificate: £274 (about £288 for applications from 8 December 2026). Councils should decide householder applications within 8 weeks of validation.
The full England rules explained
Questions about extensions in Brentwood
Do you cover Brentwood?
Yes. We cover Brentwood (CM13, CM14 and CM15) and the surrounding area, including Harold Wood and Emerson Park. The first site visit is free.
What does a two-storey extension cost in Brentwood?
Using our East of England guide, a two-storey rear extension with a 4 m × 3.5 m footprint on two floors (28 m² of new floor space) is about £57,500–£78,000 including VAT. An extension over a garage is about £32,500–£47,500.
Which other places near Brentwood do you cover?
Everywhere around it, including Harold Wood (3.6 miles), Emerson Park (4.5 miles) and Billericay (4.9 miles), and the rest of Essex.