Which postcode districts around Kew do we cover for mansard roof extension work?
Every Kew postcode district we draw in, the stock that dominates
it and the authority that validates a mansard roof extension there. Kew 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 |
|---|
| TW9 | Richmond / Kew | Georgian and Edwardian villas | Richmond / Kew sits wholly inside TW9, so Richmond Council validates every mansard roof extension submitted from an TW9 address. |
| 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. |
| SW13 | Barnes | Georgian villas, Edwardian terraces | Neighbouring Barnes, 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. |
How does a mansard roof extension differ street by street across Kew?
Roof pitch, wall build-up and plot depth change every few Kew
streets, and each one changes what a mansard roof extension can achieve at that address.
- Kew (TW9) — a mansard roof extension in Kew starts from georgian and edwardian villas, and Kew reads as Georgian and Edwardian villas around the green. Mansards read as original on Georgian terraces in TW9. Richmond Council assesses Kew mansard roof extensions against its own Kew character guidance, and the location plan we draw for Kew references Kew Gardens.
- Near Kew: 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.
- Near Kew: Richmond (TW9, TW10) — mansard roof extension work in Richmond means georgian terraces, victorian villas. Richmond is Georgian centre, riverside conservation. Mansards read as original on Georgian terraces throughout TW9. Richmond Council decides the Richmond application, and Richmond Green anchors the Richmond location plan.
- Near Kew: Twickenham (TW1, TW2) — mansard roof extension work in Twickenham means georgian fragments, victorian terraces, edwardian villas. Twickenham is Georgian and Victorian riverside town. Mansards read as original on Georgian terraces throughout TW1. Richmond Council decides the Twickenham application, and Twickenham Stadium anchors the Twickenham location plan.
- Near Kew: 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 Kew: East Sheen (SW14) — a mansard roof extension in East Sheen starts from edwardian villas, 1930s semi-detached, and East Sheen reads as Edwardian villas, 1930s semi-detached. Edwardian parapets give a mansard a clean base line in SW14. Richmond Council assesses East Sheen mansard roof extensions against its own East Sheen character guidance, and the location plan we draw for East Sheen references Sheen Lane.
- Near Kew: 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.
Does Kew planning policy restrict a mansard roof extension?
How designation changes a Kew mansard roof extension: Richmond Council maintains 72 conservation areas, including Ham Common, Richmond Green, Kew Green. Inside any of them a Kew mansard roof extension cannot rely on permitted development, and the route becomes a £548 householder application determined in 8 weeks rather than a £249 prior approval in 6 weeks. Twickenham Riverside sets the tone for Kew casework.
Kew permitted development status: there is no borough-wide direction from Richmond Council, so a mansard roof extension at a TW9 address is normally still permitted development. We certify that with a £274 Lawful Development Certificate rather than leaving a Kew sale to argue it later.
What Kew 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 Kew 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.
Who decides a mansard roof extension on the edge of Kew?
- Hounslow — adjoining Kew, with 30 conservation areas centred on W3. A mansard roof extension on the far side of the Kew line is determined by Hounslow Council, so the Kew quote for mansard roof extensions is checked against Hounslow guidance before it is issued.
- Kingston upon Thames — cross the Kew boundary and Kingston Council takes the mansard roof extension instead, applying 22 conservation areas of its own around KT1. We re-price mansard roof extensions at the Kew edge because Kingston upon Thames policy and Richmond upon Thames policy rarely align on mansard roof extension depth.
- Wandsworth — adjoining Kew, with 45 conservation areas centred on SW8. A mansard roof extension on the far side of the Kew line is determined by Wandsworth Council, so the Kew quote for mansard roof extensions is checked against Wandsworth guidance before it is issued.
- Hammersmith and Fulham — the Hammersmith and Fulham boundary runs against Richmond upon Thames, so a mansard roof extension a street from Kew is decided by Hammersmith & Fulham Council instead. Hammersmith and Fulham runs 45 conservation areas across W6 and its neighbours, which is why mansard roof extensions priced for Kew are re-checked against Hammersmith and Fulham policy whenever the Kew address sits on that edge.
Sources for this Kew 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.
