Wimborne Minster · Dorset

Two-storey rear extensions in Wimborne Minster

A two-storey rear extension is one of the most space-efficient ways to add bedrooms and living space to a house in Wimborne Minster, because the new floors share one set of foundations and one roof.

Before you start in Wimborne Minster, here's what applies.

Postcode districts
BH21
County / area
Dorset, England
Price region
South West England
Guide price
£57,500–£78,000 (£2,060–£2,780 per m²)
Approval route
It may be permitted development if it goes no more than 3 m beyond the original rear wall (counting any single-storey part) and stays 7 m from the rear boundary; otherwise it needs planning permission.
Nearest towns
Broadstone (1.9 miles), Canford Heath (2.3 miles), Ferndown (4 miles)
Distance to Bournemouth
about 6.3 miles
First visit
Free, no obligation

About a two-storey rear extension

A two-storey rear extension suits you if you need more room on both floors and have a reasonably deep garden. You get one team for the whole job: a measured survey, the design, a check on whether permitted development applies, planning drawings where they are needed, structural design, building regulations approval and the build itself, carried out by vetted teams working under S&K. Every project starts with a free site visit.

Around Wimborne Minster we also work in Broadstone, Canford Heath and Ferndown, and across the rest of Dorset. Postcode district in and near Wimborne Minster: BH21.

What it costs in Wimborne Minster

Most of the cost of a two-storey rear extension is set by its size and specification. For Wimborne Minster and the rest of South West England, our guide is £2,060–£2,780 per m² including VAT, so about £57,500–£78,000 for a 4 m × 3.5 m footprint on two floors (28 m² of new floor space). Professional fees for drawings and the structural engineer are listed separately on our prices page.

SpecPer m²A 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 Wimborne Minster

In England, a two-storey rear extension can be permitted development if it goes no more than 3 m beyond the rear wall of the original house, stays at least 7 m from the rear boundary and matches the house's materials and roof pitch. It is not permitted development in conservation areas, National Landscapes, National Parks, World Heritage Sites or the Broads. Otherwise a householder application costs £548 (or £575 for applications made from 8 December 2026).

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 Wimborne Minster homes

Depth and neighbours' light

Councils check that a two-storey rear extension does not take too much light or outlook from neighbouring windows, and many use a 45-degree line drawn from the nearest habitable window. We test this at sketch stage, so the depth you are shown is one that can realistically be approved.

Upstairs layout and windows

Bedrooms above need a window big enough for escape or a protected route to the stairs. Side-facing upstairs windows normally have to be obscure-glazed and fixed below 1.7 m, so we put the main bedroom windows in the rear wall and use roof lights where extra daylight is needed.

How we'd run your project

  1. Measure and listen

    A visit to Wimborne Minster to understand how you live in the house now and what the extra rooms need to do, plus a first look at the structure.

  2. Drawings and permission

    Our designers produce plans and elevations, then we take care of planning or permitted development checks with the council covering Wimborne Minster.

  3. Technical design

    We prepare the building regulations drawings, structural calculations and specification so the build price can be fixed.

  4. Finish and certify

    Second fix, plastering and making good, then building control's final inspection and the completion paperwork.

Questions about two-storey rear extensions in Wimborne Minster

Which postcodes do you cover around Wimborne Minster?

We cover Wimborne Minster (BH21) and nearby places including Broadstone, Canford Heath and Ferndown, plus the rest of Dorset. The first site visit is free.

How much does a two-storey rear extension cost in Wimborne Minster?

Our guide for South West England, which covers Wimborne Minster, 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.

Who handles building regulations for a project in Wimborne Minster?

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.

Will a two-storey rear extension block my neighbour's light?

It can if it is too deep or too close to the boundary, which is why councils look closely at its effect on neighbouring windows and gardens. We test the design against light and outlook early, keep the first floor shorter or set in where needed, and use a hipped roof to reduce bulk on the boundary side.

Can I have a balcony on a two-storey rear extension?

In England, balconies, verandas and raised platforms are not permitted development, so a balcony on a two-storey rear extension needs planning permission. A Juliet balcony, a guard rail across full-height doors with no platform to stand on, is often a practical alternative, but it still needs checking against the rules and the council's approach to overlooking.

Nearby

Other towns near Wimborne Minster:

Other extensions in Wimborne Minster

All two-storey extension services in Wimborne Minster · Two-storey rear extensions across Dorset

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