Bungalow and upward extensions in Windsor

Covering Windsor

Alongside Windsor, we also cover Slough, Egham (4 miles to the south-east) and Staines.

Homes in the South East

Housing across the South East mixes inter-war semis, post-war estates and older cottages in villages and market towns, so rear and side extensions, hip-to-gable lofts and garage conversions all come up regularly.

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.

Design and planning or prior approval application
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

How is an upward extension approved in Windsor?

English projects need planning clearance from the local council, building regulations sign-off from building control, and party wall notices where the work is on or near a shared boundary. We prepare and manage all three.

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 can change the price or programme?

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

How does the project run?

Tell us about the project. Call, use the guide price tool or send the form with a few photos and a postcode.
We visit and measure. A surveyor checks the house, the boundaries and the ground, and discusses what is realistic.
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.

Bungalow and upward extensions: common questions

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.

How long does it take?

About 12 to 24 weeks on site.

Who deals with the council for a project in Windsor?

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

Bungalow and upward extensions in nearby towns

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