Two-storey wraparound extensions in Derry

Useful details for planning a two-storey wraparound extension in Derry.

Postcode districts: BT48
County / area: County Londonderry, Northern Ireland
Price region: Northern Ireland
Guide price: £106,000–£145,500 (£1,890–£2,600 per m²)
Approval route: Planning permission is usually needed.
Nearest towns: New Buildings (3.1 miles), Culmore (4 miles), Eglinton (5.2 miles)
First visit: Free, no obligation

About a two-storey wraparound extension

A two-storey wraparound extension suits a house with space both beside it and behind it, where you want to transform the layout rather than add a single room. You get one design for the whole L-shape, the planning application, structural design for the corner and the openings into the house, building regulations approval and the build, managed by us and carried out by vetted teams working under S&K.

We cover Derry (BT48) and the places around it, including New Buildings (3.1 miles), Culmore (4.0 miles) and Eglinton.

What it costs in Derry

Guide prices for two-storey wraparound extensions in Northern Ireland are around £1,890–£2,600 per m² of new floor space, including VAT. For 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), that's roughly £106,000–£145,500. Design fees, structural calculations and approval fees are separate and listed on our prices page.

Spec	Per m²	An L-shaped footprint of about 28 m² wrapping the side and rear, on two floors (56 m² of new floor space)
Essential	£1,740–£2,390 per m²	£97,500–£133,500
Standard	£1,890–£2,600 per m²	£106,000–£145,500
Premium	£2,270–£3,120 per m²	£127,000–£174,500

Planning and building control in Derry

In Northern Ireland, the permitted development allowance for two-storey extensions covers rear extensions of up to 3 m that stay 7 m from the rear boundary. A wraparound adds a side element on two floors, so it normally needs a planning application. The fee is £347 per dwelling, and councils aim for an average of 15 weeks for local applications.

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.

Design points for Derry homes

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.

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.

How we'd run your project

Understand the brief
At your home in Derry 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.
Technical design
We prepare the building regulations drawings, structural calculations and specification so the build price can be fixed.
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 Derry

Which postcodes do you cover around Derry?

We cover Derry (BT48) and nearby places including New Buildings, Culmore and Eglinton, plus the rest of County Londonderry. The first site visit is free.

Who handles building control for a project in Derry?

We handle it as part of the project. What's needed in Northern Ireland: building control approval from the local council under the Building Regulations (Northern Ireland), using the Technical Booklets. We prepare the drawings and the engineer's calculations, book the inspections and pass you the completion paperwork at the end.

How long does a two-storey wraparound extension take?

Allow 4 to 8 weeks for survey and design, then the approval period (councils aim to decide local applications within an average of 15 weeks; many take longer), 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.

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.

Can a wraparound extension be part single, part two-storey?

Yes. Many wraparounds keep the rear part single storey with roof lights over the kitchen and put the two-storey part to the side. This can reduce the effect on neighbours and the cost. We set out both options at the design stage, so you can compare floor space against price before choosing.

Nearby

The same service in neighbouring towns:

Other extensions in Derry

All two-storey extension services in Derry · Two-storey wraparound extensions across County Londonderry

Tell us about your house in Derry and we'll call you back to arrange a free, no-obligation visit.