Two-storey wraparound extensions in Chorleywood

Quick reference for homeowners in Chorleywood.

Postcode districts: WD3
County / area: Hertfordshire, England
Price region: East of England
Guide price: £124,000–£170,000 (£2,210–£3,040 per m²)
Approval route: Planning permission is needed: the side part takes it outside permitted development in England.
Nearest towns: Rickmansworth (1.9 miles), Batchworth (2.6 miles), Croxley Green (3.1 miles)
Distance to Watford: about 5.1 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 Chorleywood (WD3) and the places around it, including Rickmansworth (1.9 miles), Batchworth (2.6 miles) and Croxley Green.

What it costs in Chorleywood

Using our East of England 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 £124,000–£170,000, including VAT. Bigger or more glazed designs cost more per m². Steelwork for wide openings is the item most likely to move the figure; we'll know once the engineer has designed it.

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	£2,040–£2,800 per m²	£114,000–£156,500
Standard	£2,210–£3,040 per m²	£124,000–£170,000
Premium	£2,660–£3,650 per m²	£149,000–£204,000

Planning and building regulations in Chorleywood

In England, a two-storey wraparound extension needs householder planning permission, because any extension beyond a side wall must be single storey to be permitted development. The application costs £548 (or £575 for applications made from 8 December 2026). Councils weigh the side part against the street scene and the rear part against neighbours' light and outlook, and should decide within 8 weeks of validation.

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 Chorleywood 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.

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

Look at the house
We start in Chorleywood with a free visit: measurements, photos, a look at the loft and drains, and a frank chat about budget.
Plans, then approval
Measured survey, design, then the right approval route for your house. We explain each step before we take it.
Price it properly
Once the engineer's calculations are in, we fix the build price in writing, with a clear list of what's included.
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 wraparound extensions in Chorleywood

Who handles building regulations for a project in Chorleywood?

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.

Which postcodes do you cover around Chorleywood?

We cover Chorleywood (WD3) and nearby places including Rickmansworth, Batchworth and Croxley Green, plus the rest of Hertfordshire. The first site visit is free.

How long does a two-storey wraparound extension take?

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

Can I stay at home during a wraparound extension?

Many people do, but a wraparound affects two sides of the house and usually the kitchen, so there will be weeks without a full kitchen. We plan a temporary kitchen, keep a route through the house and seal off the work area. For some families, moving out while the rear wall is opened up is easier.

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.

Nearby

We also cover places near Chorleywood, including:

Other extensions in Chorleywood

All two-storey extension services in Chorleywood · Two-storey wraparound extensions across Hertfordshire

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