Bungalow and upward extensions in London

Covering London

We cover London, including Brent, Islington, Bexley and Barking, and the towns around them.

Homes in London

Much of London’s housing is Victorian and Edwardian terraces, which is why side return extensions, rear dormers and mansards are so common. Many streets are in conservation areas, and several boroughs use Article 4 directions that remove some permitted development rights.

What is included in an upward extension in London?

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.

Design and planning or prior approval application
Staircase and changes to the ground floor layout
Full fit-out of the new rooms

How much should I budget for an upward extension?

Use these ranges to budget for bungalow and upward extensions; the survey turns them into a fixed price for the agreed specification.

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 London

In England we deal with the council’s planning team for permission or a lawful development certificate, with building control (the council or a registered building control approver) for inspections, and with neighbours under the Party Wall etc. Act 1996 where it 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.

What should I think about before starting?

The staircase takes space from the ground floor plan.
The house is exposed while the roof is off, so the sequence is planned tightly.

From first call to completion

Start with a conversation. A short call or the online form is enough for us to understand what you want to build.
Free site visit. We measure up, look at access, drains and the structure, and talk through options and budget.
Design and fixed price. You get drawings and a written price for the agreed specification before anything is ordered.
Build and hand over. Our teams build to the programme, building control inspects, and you get the completion paperwork at the end.

Your questions answered

Can I add a first floor to my bungalow?

Often yes, if the walls and foundations can carry the load and planning allows. We check the structure first.

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.

Who deals with the council for a project in London?

We do. We prepare the drawings, submit planning or permitted development paperwork if needed, and arrange building control inspections.

Also covering

Learn more about bungalow and upward extensions, or see every project we cover in London.