Two-storey extensions for semi-detached houses in Teignmouth

Teignmouth: the key facts for this kind of project.

Postcode districts: TQ14
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: Dawlish (2.8 miles), Kingsteignton (3.8 miles), Newton Abbot (5.2 miles)
Distance to Plymouth: about 30.9 miles
First visit: Free, no obligation

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

This service suits you if you own a semi-detached house and want to add bedrooms and living space without moving. On a semi, the main questions are which side to build on and how to treat the attached neighbour. You get a survey, design options, the approvals your nation needs and the build, carried out by vetted teams working under S&K.

We cover Teignmouth (TQ14) and the places around it, including Dawlish (2.8 miles), Kingsteignton (3.8 miles) and Newton Abbot.

What it costs in Teignmouth

Our guide for South West England is £2,060–£2,780 per m² including VAT. On a project with a 4 m × 3.5 m footprint on two floors (28 m² of new floor space), that puts a two-storey extension for a semi-detached house in Teignmouth at roughly £57,500–£78,000. Kitchens, bathroom fittings and flooring are priced separately so you can compare like with like.

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 Teignmouth

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 Teignmouth homes

The attached neighbour's light

A two-storey rear extension next to the party wall can take light from the neighbour's rear windows. Councils often use a 45-degree test, so the first floor may need to be shorter than the ground floor or set in from the shared boundary.

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

Visit and first ideas
One of our team visits your house in Teignmouth, checks the walls, roof and drains, and sketches out options with you.
Drawings and permission
Our designers produce plans and elevations, then we take care of planning or permitted development checks with the council covering Teignmouth.
Fixed price in writing
With approved drawings and calculations, we give you a fixed build price and a programme you can plan around.
Build it
The new structure goes up first, then we open into the house, finish inside and get the completion certificate.

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

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

Our guide for South West England, which covers Teignmouth, 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.

Which postcodes do you cover around Teignmouth?

We cover Teignmouth (TQ14) and nearby places including Dawlish, Kingsteignton and Newton Abbot, plus the rest of Devon. The first site visit is free.

Do I need planning permission for a two-storey extension for a semi-detached house in Teignmouth?

Teignmouth is in England, so England planning rules apply. 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. If in doubt, a lawful development certificate or a planning application gives you certainty before you build.

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.

Will a side extension make my semi look like a terrace?

It can if it fills the whole gap to the boundary at first floor and the neighbour does the same. Many councils ask for a first-floor gap to the side boundary or a set-back for this reason. We design the extension to keep the semi reading as one of a pair.

Nearby

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

Other extensions in Teignmouth

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

Ready to talk it through? Call us or send the form and we'll arrange a visit to your home in Teignmouth.