Which postcode districts around Barnes do we cover for mansard roof extension work?
Every Barnes postcode district we draw in, the stock that dominates
it and the authority that validates a mansard roof extension there. Barnes fees below are the
statutory England rates for 2026, not mansard roof extension estimates.
| Postcode | Area | Dominant stock | What it means for a mansard roof extension |
|---|
| SW13 | Barnes | Georgian villas, Edwardian terraces | SW13 covers Barnes only; Richmond Council handles the mansard roof extension, and Barnes case officers apply the SW13 conservation-area map. |
| TW9 | Richmond | Georgian terraces, Victorian villas | Neighbouring Richmond, where mansard roof extension work is handled by the same Richmond Council case officers. |
| TW1 | Twickenham | Georgian fragments, Victorian terraces, Edwardian villas | Neighbouring Twickenham, where mansard roof extension work is handled by the same Richmond Council case officers. |
| TW9 | Kew | Georgian and Edwardian villas | Neighbouring Kew, where mansard roof extension work is handled by the same Richmond Council case officers. |
| SW14 | East Sheen | Edwardian villas, 1930s semi-detached | Neighbouring East Sheen, where mansard roof extension work is handled by the same Richmond Council case officers. |
| TW11 | Teddington | Edwardian villas, Victorian terraces | Neighbouring Teddington, where mansard roof extension work is handled by the same Richmond Council case officers. |
| TW12 | Hampton | Georgian villas, Edwardian terraces, 1930s semi-detached | Neighbouring Hampton, where mansard roof extension work is handled by the same Richmond Council case officers. |
| TW2 | Whitton | 1930s semi-detached | Neighbouring Whitton, where mansard roof extension work is handled by the same Richmond Council case officers. |
| TW10 | Ham | Georgian villas, post-war estates | Neighbouring Ham, where mansard roof extension work is handled by the same Richmond Council case officers. |
| SW14 | Mortlake | Victorian and Edwardian terraces | Neighbouring Mortlake, where mansard roof extension work is handled by the same Richmond Council case officers. |
Which Barnes neighbourhoods suit a mansard roof extension best?
Roof pitch, wall build-up and plot depth change every few Barnes
streets, and each one changes what a mansard roof extension can achieve at that address.
- Barnes (SW13) — Georgian and Edwardian village defines Barnes, where georgian villas, edwardian terraces set what a mansard roof extension can do. Mansards read as original on Georgian terraces across SW13. Any Barnes mansard roof extension is validated by Richmond Council, with Barnes Common the usual Barnes reference point on the site plan.
- Near Barnes: East Sheen (SW14) — mansard roof extension work in East Sheen means edwardian villas, 1930s semi-detached. East Sheen is Edwardian villas, 1930s semi-detached. Edwardian parapets give a mansard a clean base line throughout SW14. Richmond Council decides the East Sheen application, and Sheen Lane anchors the East Sheen location plan.
- Near Barnes: Teddington (TW11) — a mansard roof extension in Teddington starts from edwardian villas, victorian terraces, and Teddington reads as Edwardian villas, Victorian terraces. A mansard on a Victorian terrace almost always needs full planning permission in TW11. Richmond Council assesses Teddington mansard roof extensions against its own Teddington character guidance, and the location plan we draw for Teddington references Teddington Lock.
- Near Barnes: Hampton (TW12) — mansard roof extension work in Hampton means georgian villas, edwardian terraces, 1930s semi-detached. Hampton is Georgian and Edwardian villages. Mansards read as original on Georgian terraces throughout TW12. Richmond Council decides the Hampton application, and Hampton Court Palace anchors the Hampton location plan.
- Near Barnes: Whitton (TW2) — 1930s semi-detached defines Whitton, where 1930s semi-detached set what a mansard roof extension can do. Mansards are rare on 1930s stock — the hipped roof form works against the geometry across TW2. Any Whitton mansard roof extension is validated by Richmond Council, with Whitton station the usual Whitton reference point on the site plan.
- Near Barnes: Ham (TW10) — Georgian common, post-war estate defines Ham, where georgian villas, post-war estates set what a mansard roof extension can do. Mansards read as original on Georgian terraces across TW10. Any Ham mansard roof extension is validated by Richmond Council, with Ham Common the usual Ham reference point on the site plan.
- Near Barnes: Mortlake (SW14) — a mansard roof extension in Mortlake starts from victorian and edwardian terraces, and Mortlake reads as Victorian and Edwardian terraces. A mansard on a Victorian terrace almost always needs full planning permission in SW14. Richmond Council assesses Mortlake mansard roof extensions against its own Mortlake character guidance, and the location plan we draw for Mortlake references Mortlake station.
What local planning policy applies to a mansard roof extension in Barnes?
Barnes conservation designations: there are 72 across Richmond Council, Kew Green, Hampton Wick, Twickenham Riverside among them. Designation costs a Barnes owner the permitted-development route: a mansard roof extension then needs a £548 householder application over 8 weeks, in place of the £249 prior approval route that takes 6 weeks. Richmond Green is the Barnes designation that most often changes a mansard roof extension design.
No blanket Article 4 over Barnes: Richmond Council has not withdrawn permitted development across Barnes, so a mansard roof extension outside a Barnes conservation area usually keeps it. The £274 Lawful Development Certificate is still the document a SW13 owner wants on file.
What Barnes is built from: Georgian in Richmond Green and Twickenham; Edwardian villas in Barnes and East Sheen; 1930s semi-detached in Whitton; riverside cottages along the Thames. Highest conservation area coverage in London; Royal Parks and Thames corridor add heritage layers; design quality heavily scrutinised. That mix decides the mansard roof extension route in Barnes more than the postcode does, and it is what a Richmond Council case officer reads first. A householder application costs £548 paid to Richmond Council direct, with 8 weeks to a decision once validated.
Which neighbouring authorities border Barnes?
- Hounslow — the Hounslow boundary runs against Richmond upon Thames, so a mansard roof extension a street from Barnes is decided by Hounslow Council instead. Hounslow runs 30 conservation areas across W3 and its neighbours, which is why mansard roof extensions priced for Barnes are re-checked against Hounslow policy whenever the Barnes address sits on that edge.
- Kingston upon Thames — adjoining Barnes, with 22 conservation areas centred on KT1. A mansard roof extension on the far side of the Barnes line is determined by Kingston Council, so the Barnes quote for mansard roof extensions is checked against Kingston upon Thames guidance before it is issued.
- Wandsworth — adjoining Barnes, with 45 conservation areas centred on SW8. A mansard roof extension on the far side of the Barnes line is determined by Wandsworth Council, so the Barnes quote for mansard roof extensions is checked against Wandsworth guidance before it is issued.
- Hammersmith and Fulham — adjoining Barnes, with 45 conservation areas centred on W6. A mansard roof extension on the far side of the Barnes line is determined by Hammersmith & Fulham Council, so the Barnes quote for mansard roof extensions is checked against Hammersmith and Fulham guidance before it is issued.
Sources for this Barnes mansard roof extension page: borough policies maps and
conservation-area registers (2025–26), Royal Mail postcode district boundaries,
the Town and Country Planning (Fees for Applications) (England) Regulations, the Town
and Country Planning (General Permitted Development) (England) Order 2015 as amended,
and the Party Wall etc. Act 1996.
