Wraparound extension in Merton: Planning Permission Guide
Your guide to wraparound extensions in Merton — combining rear and side extensions under one project.
Based on 53 decided applications in Merton over 24 months (47 granted, 6 refused).
Merton has conservation areas including Wimbledon Village, Wimbledon Common, Mitcham Cricket Green, and Cannizaro Park. Listed buildings cluster around Wimbledon Common and Merton Abbey Mills. Wimbledon Common is Metropolitan Common Land with its own byelaws near the edges. Article 4 Directions cover parts of Wimbledon Village. The borough has a mix of affluent Edwardian housing around Wimbledon and Victorian terrace stock in Mitcham and Colliers Wood.
Personalised odds
5 nearest comparables & refusal reasons for your address.
Get my report — £9See a sample →Recent wraparound extension decisions in Merton
The 5 most recent decided applications. Addresses redacted to postcode area.
CHANGES TO FENESTRATION TO SIDE AND REAR ELEVATIONS
APPLICATION FOR A LOFT CONVERSION AND ERECTION OF A SIDE AND REAR DORMER EXTENSION WITH A REAR JULIET BALCONY TO UTILISE THE EMPTY LOFT…
APPLICATION FOR REAR AND SIDE RETURN EXTENSIONS, EACH EXTENSION TO BE 3M DEEP.
ERECTION OF A SIDE AND REAR SINGLE STOREY EXTENSION AND ERECTION OF A L-SHAPED REAR DORMER.
APPLICATION FOR PRIOR APPROVAL IN RESPECT OF THE REMOVAL OF 1NO EXISTING 8M L2 MONOPOLE, 3NO EXISTING ANTENNAS AND 2NO EXISTING SIDE-BY-S…
These are borough-wide. See the 5 nearest to your address.
Get my report — £9Permitted Development Rules
Enlargement, improvement or other alteration of a dwellinghouse
GPDO 2015, Schedule 2, Part 1, Class A
A wraparound extension combines a rear and side extension. It's assessed under Part 1, Class A of the GPDO and must comply with the limits for both rear depth and side width.
Key dimension limits
These are the maximum GPDO limits for a detached house with no constraints. Your actual limits depend on your property type, location, and any planning restrictions.
Enter your postcode to see the personalised limits for your wraparound extension.
Check my limitsTypical Costs in London
Wraparound extensions cost more than a simple rear or side extension due to the larger footprint and more complex structural requirements.
Cost per m²
construction rate
Typical total
Based on 20–30 m²
Typically includes
Typically excludes
Combines rear and side extension. Costs at the higher end due to larger footprint and structural complexity.
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Get my estimateWhich Professionals Do You Need?
Wraparound extensions have complex geometry with multiple roof junctions and typically benefit from professional design input.
You'll need a party wall surveyor for this project.
Wraparound extensions have complex geometry with multiple roof junctions that benefit from professional design.
Typical fee: £2,000–£5,000 (Plans + Building Regs)
Single storey extensions typically need structural calculations for any openings in existing walls and for foundations.
Typical fee: £500–£1,500
Your semi-detached house shares a boundary with neighbours. Extensions and loft work within 3 metres of a shared wall trigger the Party Wall Act.
Typical fee: £700–£1,500 (per neighbour)
This guidance is based on a typical semi-detached house with no special constraints. Listed buildings, conservation areas, and attached properties may require additional professional input.
Find out exactly which professionals you need for your wraparound extension.
Get personalised guidanceConservation Areas & Listed Buildings
In conservation areas, the side element of a wraparound extension is not permitted development. The rear element is limited to 3 metres depth.
Properties in conservation areas often have reduced permitted development rights. Some project types (like side extensions) lose PD rights entirely. An Article 4 Direction can remove additional PD rights.
Listed buildings (Grade I, II*, or II) have no permitted development rights at all. Any external alteration requires Listed Building Consent in addition to any planning permission. An architect experienced in heritage work is essential.
Check if your property is in a conservation area or has other planning constraints.
Check my propertyFrequently Asked Questions
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