Llandaff · Cardiff and the Vale of Glamorgan

Two-storey wraparound extensions in Llandaff

Adding a two-storey wraparound extension in Llandaff gives you two new rooms stacked on one footprint. Here's how we'd approach it, what it typically costs and the rules that apply in Wales.

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

Postcode districts
CF5
County / area
Cardiff and the Vale of Glamorgan, Wales
Price region
Wales
Guide price
£111,000–£152,000 (£1,980–£2,710 per m²)
Approval route
Usually needs planning permission, because the combined side and rear works rarely meet every permitted development test.
Nearest towns
Whitchurch (Cardiff and the Vale of Glamorgan) (1.3 miles), Cardiff (1.9 miles), Rhiwbina (2.4 miles)
Distance to Cardiff
about 1.9 miles
First visit
Free, no obligation

About a two-storey wraparound extension

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.

Around Llandaff we also work in Whitchurch (Cardiff and the Vale of Glamorgan), Cardiff and Rhiwbina, and across the rest of Cardiff and the Vale of Glamorgan. Postcode district in and near Llandaff: CF5.

What it costs in Llandaff

Using our Wales rates, a two-storey wraparound extension with an L-shaped footprint of about 28 m² wrapping the side and rear, on two floors (56 m² of new floor space) comes to about £111,000–£152,000, including VAT. Bigger or more glazed designs cost more per m². Professional fees for drawings and the structural engineer are listed separately on our prices page.

SpecPer m²An L-shaped footprint of about 28 m² wrapping the side and rear, on two floors (56 m² of new floor space)
Essential£1,820–£2,500 per m²£102,000–£140,000
Standard£1,980–£2,710 per m²£111,000–£152,000
Premium£2,370–£3,260 per m²£133,000–£182,500

Planning and building regulations in Llandaff

In Wales, a wraparound would have to pass both the side and rear tests to be permitted development: 10.5 m to the opposite side boundary, a 1 m set-back from the front and no more than 50% added width, plus the 4 m and 3 m rear depth limits and 10.5 m to the rear boundary. Many wraparounds therefore need a householder application, which costs £585.

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).

Design points for Llandaff homes

Daylight to the middle

A deep L-shaped plan can leave the middle of the ground floor dark, because the old rear rooms are now enclosed. We use wide rear openings, a well-placed stair and, where part of the extension is single storey, roof lights, while keeping total glazing within the Part L allowance.

Phasing the build

A wraparound touches two sides of the house at once, so the kitchen and often the rear rooms are out of use for part of the build. We plan the sequence so you keep a working kitchen and bathroom for as long as possible, or advise when moving out briefly makes sense.

How we'd run your project

  1. Start at your house

    We come to your home in Llandaff, measure up, check the ground floor walls and roof structure, and note anything near the boundaries.

  2. Plans, then approval

    Measured survey, design, then the right approval route for your house. We explain each step before we take it.

  3. Structure and building control

    A structural engineer sizes the foundations and steels, and we get building regulations approval before work starts.

  4. Build and sign-off

    Vetted teams working under S&K build the extension, and we arrange the building control completion certificate at the end.

Questions about two-storey wraparound extensions in Llandaff

How long does a two-storey wraparound extension take?

Allow 4 to 8 weeks for survey and design, then the approval period (councils normally decide householder applications within 8 weeks), 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.

Which postcodes do you cover around Llandaff?

We cover Llandaff (CF5) and nearby places including Whitchurch (Cardiff and the Vale of Glamorgan), Cardiff and Rhiwbina, plus the rest of Cardiff and the Vale of Glamorgan. The first site visit is free.

Do I need planning permission for a two-storey wraparound extension in Llandaff?

Llandaff is in Wales, so Wales planning rules apply. Usually needs planning permission, because the combined side and rear works rarely meet every permitted development test. If in doubt, a lawful development certificate or a planning application gives you certainty before you build.

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.

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.

Nearby

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

Other extensions in Llandaff

All two-storey extension services in Llandaff · Two-storey wraparound extensions across Cardiff and the Vale of Glamorgan

Send us your postcode and a few details. We'll get back to you to arrange a visit and talk through your options.

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