Covering Barnes
We work in Barnes (SW13) and the places around it, including Chiswick, Putney and Fulham.
Homes in London
London projects often mean working on period terraces with neighbours on both sides, tight access through the house and conservation area controls, so careful planning and party wall work matter as much as the build.
What does an upward extension involve?
The first question is whether the existing walls and foundations can carry the extra load, so we start with a structural survey. Then we design either a full first floor or a raised roof with dormers, handle planning or prior approval, and build the new storey while protecting the floor below.
- Structural survey of walls and foundations
- Roof removal and temporary weather protection
- Full fit-out of the new rooms
How much should I budget for an upward extension?
Indicative costs for bungalow and upward extensions. London and the South East usually sit towards the top of each range.
| Bungalow and upward extensions | Guide price incl. VAT |
|---|---|
| Chalet conversion with dormers (total) | £45,000 to £85,000 |
| New first floor, standard specification | £2,200 to £2,800 per m² |
| New first floor, good specification | £2,800 to £3,300 per m² |
| New first floor, high specification | £3,300 to £3,800 per m² |
Planning and building rules in Barnes
Projects in England go through two separate checks. Planning (or confirmation that the work is permitted development) comes from the district, borough or unitary council, and building regulations approval comes from the council’s building control team or a registered building control approver. Where work touches a shared wall or digs near a neighbour’s foundations, the Party Wall etc. Act 1996 applies.
In England, Class AA permitted development allows an extra storey on many detached and semi-detached houses built between July 1948 and October 2018, subject to a prior approval application covering design, neighbours’ amenity and other matters. Houses in conservation areas and other protected land need full planning permission, as do most chalet conversions with front dormers.
What can affect an upward extension?
- Some bungalow foundations need strengthening before a storey can be added.
- The house is exposed while the roof is off, so the sequence is planned tightly.
What happens after I enquire?
- Tell us about the project. Call, use the guide price tool or send the form with a few photos and a postcode.
- Survey at your house. We look at the existing structure, services and access, and agree what the design needs to achieve.
- Drawings, approvals, written quote. We prepare the design, apply for the approvals it needs, and give you a fixed price in writing.
- We build it. Work follows an agreed programme, with inspections at each stage and a final sign-off.
What people ask before starting
How much does it cost to add a storey?
Around £2,200 to £3,800 per square metre of new floor including VAT, or £45,000 to £85,000 for a chalet conversion with dormers.
Is an upward extension permitted development?
In England, Class AA allows it on many post-1948 houses through a prior approval application. Elsewhere planning permission is needed.
Who deals with the council for a project in Barnes?
We do. We prepare the drawings, submit planning or permitted development paperwork if needed, and arrange building control inspections.
Bungalow and upward extensions near Barnes
- Bungalow and upward extensions in Chiswick
- Bungalow and upward extensions in Putney
- Bungalow and upward extensions in Fulham
- Bungalow and upward extensions in Shepherd's Bush
Learn more about bungalow and upward extensions, or see every project we cover in Barnes.

