End-of-Terrace Two-Storey Extensions

What you get

This service suits you if you own an end-of-terrace house with land to the side or a reasonable rear garden. You get a design that keeps the terrace looking right, a planning application or permitted development check depending on your nation, structural design, party wall handling in England and Wales and the build, carried out by vetted teams working under S&K.

It suits you if…

You own an end-of-terrace house with a side garden or drive
You need an extra bedroom and want to keep the rear garden
Your house is on a corner plot and you want to know what the council may allow
You want a rear extension that respects the attached neighbour

Line drawing: existing house in outline, new work in brick, blue dashed line at first-floor level.

Design points that matter

Continuing the terrace roof

A side extension on an end-of-terrace house usually continues the roofline of the row, so the pitch, eaves height and tiles must match. A small step down in the ridge and a set-back at the front often help the extension read as an addition rather than an extra house.

Corner plots

Many end-of-terrace houses sit on corners, where the side wall faces a road. In England nothing can be built beyond a side wall that fronts a highway under permitted development, and councils guard open corners, so we keep a gap to the pavement and design the side wall as a second front.

The attached neighbour at the rear

A rear extension sits against the next house in the terrace, whose rear windows are often close to the shared wall. The first floor may need to be shorter or set in to protect their light, and Party Wall Act notices are likely in England and Wales.

Older walls and foundations

Many terraces are older, with shallow footings and solid walls. Tying a new two-storey extension into them needs a careful structural design and sometimes movement joints, and we check the gable wall and its foundations before the design is fixed.

Planning and approvals by nation

England

In England, a two-storey side extension on an end-of-terrace house always needs planning permission, costing £548 (or £575 for applications made from 8 December 2026). A two-storey rear extension can be permitted development within 3 m of the original rear wall and 7 m from the rear boundary. On a corner plot, nothing can go beyond a side wall that fronts a highway under 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.

Wales

In Wales, a two-storey side extension on an end-of-terrace house can be permitted development if it is at least 10.5 m from the boundary opposite the side wall, set back at least 1 m from the front and adds no more than 50% to the house's width. Narrow side plots and corner sites rarely meet this, so a householder application costing £585 is common.

Approval in Wales: Householder planning application: £585. Councils normally decide householder applications within 8 weeks.

Building regulations: Building regulations approval under the Welsh Approved Documents, which differ from England's in places (notably energy efficiency).

Scotland

In Scotland, Class 1B permitted development needs a two-storey extension to be at least 10 m from every boundary and not on an elevation fronting a road. An end-of-terrace house is attached on one side, so a two-storey extension needs a householder application (£371, decided within two months) and then a building warrant.

Approval in Scotland: Householder planning application: £371. Councils have two months to decide a local planning application.

Building standards: A building warrant from the council's building standards service before work starts, and a completion certificate at the end. Scotland uses its own Technical Handbooks.

Northern Ireland

In Northern Ireland, a two-storey rear extension 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 height, materials and roof pitch conditions. A two-storey side extension normally needs a planning application costing £347 per dwelling. There is no Party Wall Act.

Approval in Northern Ireland: Planning application for works to a house: £347. Councils aim to decide local applications within an average of 15 weeks; many take longer.

Building control: Building control approval from the local council under the Building Regulations (Northern Ireland), using the Technical Booklets.

Guide price

As a guide, a two-storey side extension to an end-of-terrace house costs £86,000–£115,500 including VAT at 20% for a 3 m × 7 m footprint on two floors (42 m² of new floor space), based on West Midlands prices and our Standard spec; London and the South East are higher.

Guide prices by region
Region	Per m² of new floor	Typical project
London	£2,460–£3,300 per m²	£103,500–£138,500
South East England	£2,260–£3,030 per m²	£94,500–£127,000
East of England	£2,110–£2,830 per m²	£88,500–£119,000
South West England	£2,110–£2,830 per m²	£88,500–£119,000
West Midlands	£2,050–£2,750 per m²	£86,000–£115,500
East Midlands	£2,010–£2,700 per m²	£84,500–£113,000
North West England	£1,950–£2,610 per m²	£82,000–£109,500
Yorkshire and the Humber	£1,890–£2,530 per m²	£79,000–£106,500
North East England	£1,840–£2,480 per m²	£77,500–£104,000
Wales	£1,890–£2,530 per m²	£79,000–£106,500
Scotland	£1,930–£2,580 per m²	£81,000–£108,500
Northern Ireland	£1,800–£2,420 per m²	£76,000–£101,500

Typical project: a 3 m × 7 m footprint on two floors (42 m² of new floor space). Including VAT at 20%, Standard spec. Essential spec is about 8% less, Premium about 20% more. See all prices and fees or work out your own guide price.

What's included

Free site visit
Measured survey, priced in writing with the design stage
Design that continues the terrace roofline
Planning application or permitted development check
Party wall notices in England and Wales
Structural design for older walls and footings
The build, carried out by vetted teams working under S&K

How it works

Free site visit
We look at your house, the boundaries, access and drains, and talk through what you need the new space to do.
Design and approval
Measured survey and drawings, then planning permission or a lawful development certificate, depending on the rules where you live.
Engineering and fixed price
Structural calculations and building regulations approval, then a fixed build price in writing.
Build and sign-off
Vetted teams working under S&K build it, and we arrange the completion certificate.

Questions about two-storey extensions for end-of-terrace houses

Can I build a two-storey side extension on a corner plot?

Often, but it needs planning permission and careful design. Councils protect the openness of corners and the view along the road, so they usually expect a gap to the pavement, a set-back from the front and a side wall with windows rather than a blank wall. We check local guidance and nearby examples first.

Will my end-of-terrace extension look like a new house on the end?

It should not, if it is designed well. A slightly lower ridge, a set-back from the front wall and a different front door position help it read as an extension. Councils often ask for this to avoid an extension that looks like an extra terraced house.

Do I need a party wall agreement for an end-of-terrace extension?

In England and Wales you are likely to need Party Wall Act notices for a rear extension, because it usually involves the shared wall or digging near the neighbour's foundations. Notices for work to a party wall need 2 months and for excavation 1 month. Scotland and Northern Ireland handle this under common law and title deeds.

Can an end-of-terrace house have a wraparound extension?

Yes, if there is room to the side and rear. It combines a side extension over the open plot with a rear extension, and it always needs planning permission in England. It gives a large open-plan ground floor, but it also affects the attached neighbour and the street, so we test it carefully.

Are old terrace foundations strong enough to extend next to?

Usually, but they need checking. Older terraces often have shallow brick footings, and a new two-storey extension sits on deeper, modern foundations alongside them. The structural engineer designs the junction so the two can move slightly without cracking, and we dig trial holes to see what is there before the design is fixed.

Related services

Two-storey side extensions

A two-storey side extension is a new two-floor addition built into the space beside your house, often over a driveway or side passage.

Learn more

Two-storey wraparound extensions

A two-storey wraparound extension is an L-shaped addition that extends both the side and the rear of your house, on two floors.

Learn more

Party wall notices for extensions

A party wall notice is a formal written notice that you must give your neighbours under the Party Wall etc. Act 1996 before certain work on or near a shared wall or boundary in England and Wales.