Why a wraparound costs more than its two halves
A rear extension is judged against its length. A side return is judged against its height and width. A wraparound joins them at the corner of the house, where the roof, the drainage and the structure all change direction, and the officer judges the whole as one enlargement.
Our fee is £855 drawings + £150 survey (£1,005 total). The extra work is the corner: a roof that has to resolve two pitches, an opening that may run the full width of the back of the house, and a structure that has to be calculated as a whole.
How the permitted development limits add up
Class A treats a combined extension as one. It bars development where any total enlargement, being the new part together with any existing enlargement it joins, would exceed the limits for the side and rear parts.
In practice that means the side part must be single storey, no higher than 4 metres and no wider than half the original house, and the rear part must stay within 3 metres (4 metres if detached), or 6 and 8 metres through prior approval. The eaves must stay at or below 3 metres within 2 metres of a boundary.
Where the house sits in a conservation area, the side part is not permitted at all, because Class A bars an extension beyond a side wall on that land. Then the whole wraparound goes through a householder application, and the council fee is £548.
Neighbours, boundaries and structure
A wraparound usually puts a new wall on or beside the boundary. If you build a new wall on the line of junction, section 1 of the Party Wall Act requires notice at least one month before the work starts. If you excavate deeper foundations near a neighbour, section 6 applies as well.
The structure matters just as much. The opening at the back of a wraparound is wide, and the corner steel carries the roof in two directions. The calculations cost £389 on top of our drawings and are not optional for this type of job.
The Community Infrastructure Levy rarely adds to the bill: GOV.UK guidance says residential extensions under 100 square metres that do not create a new dwelling are exempt.
What the national figures say about extensions
Large householder extensions made up 57% of the permitted development applications reported in England in April to June 2026. That makes large extensions the biggest single group of these applications, which is why the limits are worth drawing carefully.
By the numbers
4 m
The highest a single-storey extension past a side wall may be under permitted development.
Half
The widest the side part may be, as a share of the width of the original house.
3 m / 4 m
How far the rear part may reach past the original rear wall on an attached or detached house.
Total
The new part plus any existing enlargement it joins is tested together against the limits.
£548
Council fee for a householder application for one house from 1 April 2026.
Source: Planning fees: annual indexation from 1 April 2026 (GOV.UK)
1 month
Minimum notice before building a new wall on the line of junction with a neighbour.
Source: Party Wall etc. Act 1996, section 1: new building on the line of junction (legislation.gov.uk)
100 m²
Residential extensions below this size, with no new dwelling, are exempt from the Community Infrastructure Levy.
Source: Community Infrastructure Levy, planning practice guidance (GOV.UK)
57%
Share of permitted development applications that were large householder extensions, April to June 2026.
Source: Planning applications in England: April to June 2026, section 3.18 (GOV.UK)
Wraparound extension costs: common questions
Is a wraparound permitted development?
It can be, if both parts meet their limits and the house is not on article 2(3) land such as a conservation area. We check each limit against the survey before we draw.
Can I build the side return first and the rear later?
Yes, but the second part is then tested together with the first, because Class A counts the total enlargement. Drawing both parts at the start avoids a surprise at the later stage.
Do I need both a planning application and a Lawful Development Certificate?
No. A planning permission is its own proof. A certificate is for work you believe is permitted development, and costs half the planning fee.
Sources
- General Permitted Development Order 2015, Schedule 2, Part 1, Class A: house extensions (legislation.gov.uk)
- Planning fees: annual indexation from 1 April 2026 (GOV.UK)
- Party Wall etc. Act 1996, section 1: new building on the line of junction (legislation.gov.uk)
- Community Infrastructure Levy, planning practice guidance (GOV.UK)
- Planning applications in England: April to June 2026, section 3.18 (GOV.UK)
About the author. Ben Shaukat is Managing Director of Property Architecture Ltd, which trades as Planning Drawings.
Published by Planning Drawings. Checked against the sources above on . Planning rules change; check your council before you build.