Two-storey wraparound extensions in Cambridgeshire

Cambridgeshire at a glance

Nation: England
Price region: East of England
Postcode areas: CB, PE, SG
Towns covered: 13 listed below, plus surrounding villages
Approval route: Planning permission is needed: the side part takes it outside permitted development in England.
Site visits: Free, no obligation

What a two-storey wraparound extension involves

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.

Cambridgeshire towns we list: Peterborough (PE1), Cambridge (CB1), Wisbech (PE13), St Neots (PE19), Huntingdon (PE28) and March (PE15). Every other address in Cambridgeshire is covered as well.

Guide price in the East of England

Our guide for the East of England is £2,210–£3,040 per m² including VAT. On a project with an L-shaped footprint of about 28 m² wrapping the side and rear, on two floors (56 m² of new floor space), that puts a two-storey wraparound extension in Cambridgeshire at roughly £124,000–£170,000. Steelwork for wide openings is the item most likely to move the figure; we'll know once the engineer has designed it.

Spec	Per m²	Typical project
Essential	£2,040–£2,800 per m²	£114,000–£156,500
Standard	£2,210–£3,040 per m²	£124,000–£170,000
Premium	£2,660–£3,650 per m²	£149,000–£204,000

Rules in England

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.

The Party Wall etc. Act 1996 applies, so notices may be needed for work on or near a shared wall or boundary.

Getting the design right

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.

Two roofs that meet

A wraparound needs the side roof and rear roof to join cleanly, often with a valley or hip where they meet. Getting pitches and ridge heights right keeps rainwater moving and avoids a bulky mass at the back corner, which neighbours and planners notice.

How we work in Cambridgeshire

Understand the brief
At your home in Cambridgeshire we agree what you need: bedroom count, bathroom, kitchen space, and how much garden you want to keep.
Plans, then approval
Measured survey, design, then the right approval route for your house. We explain each step before we take it.
Price it properly
Once the engineer's calculations are in, we fix the build price in writing, with a clear list of what's included.
Build
Foundations, walls, floor, roof, windows, then first and second fix. We break through into the house as late as we can.

Towns we cover in Cambridgeshire

Two-storey wraparound extensions in Cambridgeshire: questions

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

In the East of England our guide is £2,210–£3,040 per m² including VAT, so about £124,000–£170,000 for an L-shaped footprint of about 28 m² wrapping the side and rear, on two floors (56 m² of new floor space). Essential and Premium specs move that by roughly 8% down or 20% up.

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.

How much floor space does a wraparound extension add?

It depends on the width of the side plot and the depth at the rear. Our guide prices are based on a typical wraparound with an L-shaped footprint of about 28 m² wrapping the side and rear, on two floors (56 m² of new floor space). Yours may be larger or smaller, and the measured survey shows what your plot can take.

Will I need planning permission in Cambridgeshire?

Cambridgeshire is in England. Planning permission is needed: the side part takes it outside permitted development in England.

Neighbouring areas

All extension services in Cambridgeshire · About two-storey wraparound extensions