Two-storey extensions for semi-detached houses in Brixham

Useful details for planning a two-storey extension for a semi-detached house in Brixham.

Postcode districts: TQ5 and TQ6
County / area: Devon, England
Price region: South West England
Guide price: £57,500–£78,000 (£2,060–£2,780 per m²)
Approval route: Depends on position: a two-storey rear extension may be permitted development (3 m deep, 7 m from the rear boundary); a two-storey side extension needs planning permission.
Nearest towns: Paignton (3.7 miles), Torquay (4.7 miles), Cockington (5.1 miles)
Distance to Plymouth: about 27.7 miles
First visit: Free, no obligation

About a two-storey extension for a semi-detached house

A two-storey extension for a semi-detached house is a two-floor addition to the rear, the open side, or both, designed around the attached neighbour on one side. The rear is often the simplest option and can sometimes be permitted development, while a side extension uses the gap on the detached side. Both need care with the shared party wall and the neighbour's light.

Brixham sits about 27.7 miles from Plymouth. Closer to home, Paignton is 3.7 miles away and Torquay 4.7 miles.

What it costs in Brixham

Using our South West England rates, a two-storey extension for a semi-detached house with a 4 m × 3.5 m footprint on two floors (28 m² of new floor space) comes to about £57,500–£78,000, including VAT. Bigger or more glazed designs cost more per m². These are guides, not quotes. Ground conditions, steelwork and access can move the figure either way.

Spec	Per m²	A 4 m × 3.5 m footprint on two floors (28 m² of new floor space)
Essential	£1,900–£2,560 per m²	£53,000–£71,500
Standard	£2,060–£2,780 per m²	£57,500–£78,000
Premium	£2,470–£3,340 per m²	£69,000–£93,500

Planning and building regulations in Brixham

In England, a two-storey rear extension on a semi can be permitted development if it goes no more than 3 m beyond the original rear wall and stays 7 m from the rear boundary, with matching materials and roof pitch. A two-storey side or wraparound extension always needs planning permission, costing £548 (or £575 for applications made from 8 December 2026). Protected areas such as conservation areas exclude two-storey rear permitted development.

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 Brixham homes

Rear, side or both

On a semi, a rear extension sits against the attached neighbour, while a side extension faces the detached neighbour and the street. We compare the space, cost and approval route for each, and for a wraparound, before you commit to one design.

Keeping the pair balanced

Semis are designed as matching pairs, and a side extension changes that balance. Setting the side extension back from the front wall and keeping its ridge lower helps the pair still read as a pair, which councils' design guides commonly ask for.

How we'd run your project

Look at the house
We start in Brixham with a free visit: measurements, photos, a look at the loft and drains, and a frank chat about budget.
Get it approved
Once you're happy with the design we submit it to the council for Brixham and deal with any questions from the planning officer.
Engineer it
Foundations sized for two floors, steels for any openings, and building control approval, all before anyone starts on site.
Build and hand over
We manage the build from groundworks to decoration-ready finish and hand over with the completion paperwork.

Questions about two-storey extensions for semi-detached houses in Brixham

Which postcodes do you cover around Brixham?

We cover Brixham (TQ5 and TQ6) and nearby places including Paignton, Torquay and Cockington, plus the rest of Devon. The first site visit is free.

How much does a two-storey extension for a semi-detached house cost in Brixham?

Our guide for South West England, which covers Brixham, is £2,060–£2,780 per m² including VAT. A typical project with a 4 m × 3.5 m footprint on two floors (28 m² of new floor space) comes to about £57,500–£78,000. Design and approval fees are extra, and we fix the build price in writing once the design is agreed.

Who handles building regulations for a project in Brixham?

We handle it as part of the project. What's needed in England: building regulations approval (full plans recommended) from the council or a registered building control approver, with a completion certificate at the end. We prepare the drawings and the engineer's calculations, book the inspections and pass you the completion paperwork at the end.

What if my neighbour has already extended?

That often helps. An existing extension next door can reduce the effect of yours on their light, and may show what the council accepts on your street. It can also mean building alongside their wall, so we check its position, foundations and any windows facing your plot at the survey.

Should I extend my semi to the side or the rear?

It depends on your plot and what you need. A rear extension keeps the side drive and can sometimes be permitted development, but it affects the attached neighbour. A side extension keeps the rear garden but always needs planning permission in England. We compare both at the free site visit.

Nearby

Close to Brixham? We work across the area, including:

Other extensions in Brixham

All two-storey extension services in Brixham · Two-storey extensions for semi-detached houses across Devon

Book a free site visit in Brixham and we'll tell you what's possible, what approvals you need and what the design stage would cost.