Crowthorne · Berkshire

Two-storey wraparound extensions in Crowthorne

Adding a two-storey wraparound extension in Crowthorne gives you two new rooms stacked on one footprint. Here's how we'd approach it, what it typically costs and the rules that apply in England.

Crowthorne: the key facts for this kind of project.

Postcode districts
RG45
County / area
Berkshire, England
Price region
South East England
Guide price
£132,500–£181,500 (£2,360–£3,250 per m²)
Approval route
Planning permission is needed: the side part takes it outside permitted development in England.
Nearest towns
Sandhurst (1.6 miles), Yateley (2.5 miles), Camberley (3.1 miles)
Distance to Reading
about 9.7 miles
First visit
Free, no obligation

About a two-storey wraparound extension

A two-storey wraparound extension is an L-shaped addition that extends both the side and the rear of your house, on two floors. It gives one of the largest gains in floor space of any extension, typically a big open-plan kitchen and living area below and two or more bedrooms or bathrooms above. In England it needs planning permission, because the side part is more than one storey.

We cover postcode district RG45 in and around Crowthorne, along with neighbouring Sandhurst, Yateley and Camberley.

What it costs in Crowthorne

Expect a two-storey wraparound extension in Crowthorne to land somewhere around £132,500–£181,500 for an L-shaped footprint of about 28 m² wrapping the side and rear, on two floors (56 m² of new floor space). Our South East England guide rate is £2,360–£3,250 per m², including VAT. Steelwork for wide openings is the item most likely to move the figure; we'll know once the engineer has designed it.

SpecPer m²An L-shaped footprint of about 28 m² wrapping the side and rear, on two floors (56 m² of new floor space)
Essential£2,180–£2,990 per m²£122,000–£167,000
Standard£2,360–£3,250 per m²£132,500–£181,500
Premium£2,840–£3,890 per m²£159,000–£218,000

Planning and building regulations in Crowthorne

In England, a two-storey wraparound extension needs householder planning permission, because any extension beyond a side wall must be single storey to be permitted development. The application costs £548 (or £575 for applications made from 8 December 2026). Councils weigh the side part against the street scene and the rear part against neighbours' light and outlook, and should decide within 8 weeks of validation.

Approval in England: Householder planning application: £548 (or £575 for applications made from 8 December 2026). Lawful development certificate: £274 (about £288 for applications from 8 December 2026). Councils should decide householder applications within 8 weeks of validation.

Building regulations: Building regulations approval (full plans recommended) from the council or a registered building control approver, with a completion certificate at the end.

Design points for Crowthorne homes

The corner post

At the outside corner of the L, there is no existing wall to carry the floor above. Opening the ground floor fully usually means a steel frame or a corner post, and the engineer's design sets how slim it can be. We decide early whether you want a clear corner or a visible post.

Daylight to the middle

A deep L-shaped plan can leave the middle of the ground floor dark, because the old rear rooms are now enclosed. We use wide rear openings, a well-placed stair and, where part of the extension is single storey, roof lights, while keeping total glazing within the Part L allowance.

How we'd run your project

  1. Look at the house

    We start in Crowthorne with a free visit: measurements, photos, a look at the loft and drains, and a frank chat about budget.

  2. Plans, then approval

    Measured survey, design, then the right approval route for your house. We explain each step before we take it.

  3. Detail and price

    Construction drawings, engineer's calculations and building control sign-off, then a written fixed price for the build.

  4. Finish and certify

    Second fix, plastering and making good, then building control's final inspection and the completion paperwork.

Questions about two-storey wraparound extensions in Crowthorne

Which postcodes do you cover around Crowthorne?

We cover Crowthorne (RG45) and nearby places including Sandhurst, Yateley and Camberley, plus the rest of Berkshire. The first site visit is free.

How long does a two-storey wraparound extension take?

Allow 4 to 8 weeks for survey and design, then the approval period (councils should decide householder applications within 8 weeks of validation), then 4 to 8 weeks of technical design, which can overlap. The build itself usually takes 14 to 20 weeks, longer for large or complex designs.

How much does a two-storey wraparound extension cost in Crowthorne?

Our guide for South East England, which covers Crowthorne, is £2,360–£3,250 per m² including VAT. A typical project with an L-shaped footprint of about 28 m² wrapping the side and rear, on two floors (56 m² of new floor space) comes to about £132,500–£181,500. Design and approval fees are extra, and we fix the build price in writing once the design is agreed.

Is a wraparound extension better than separate side and rear extensions?

Building both at once usually costs less than two separate projects, because you pay for one set-up, one scaffold, one roof junction and one set of approvals. It also lets the layout be designed as a whole. The trade-off is a larger single outlay and a longer build, often 16 to 24 weeks at this size.

Does a wraparound extension need steel?

Almost always. Opening the corner of the house and the old rear wall to make one open-plan space means steel beams, and often a steel post or frame at the outside corner. The structural engineer sizes these, and the steel is ordered once the design is fixed, which is one reason a wraparound needs careful sequencing.

Nearby

Other towns near Crowthorne:

Other extensions in Crowthorne

All two-storey extension services in Crowthorne · Two-storey wraparound extensions across Berkshire

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