Two-storey annexe extensions in Warwickshire

Warwickshire at a glance

Nation: England
Price region: West Midlands
Postcode areas: B, CV
Towns covered: 10 listed below, plus surrounding villages
Approval route: Planning permission is needed: in England, permitted development only allows single-storey extensions to the side.
Site visits: Free, no obligation

What a two-storey annexe extension involves

A two-storey annexe extension is an attached extension laid out as self-contained living space on two floors, usually with a living area and kitchenette below and a bedroom and shower room above, for a relative living with the family. It stays part of the main house rather than a separate home. Planning and council tax rules treat it differently from a separate dwelling.

The main places we list in Warwickshire are Nuneaton (CV10), Rugby (CV21), Leamington Spa (CV31), Warwick (CV34), Bedworth (CV12) and Stratford-upon-Avon (B49). We cover the villages in between too.

Guide price in the West Midlands

For budgeting in Warwickshire, allow around £86,000–£115,500 (plus kitchenette and shower room fittings, priced to your choice) for a two-storey annexe extension with a 3 m × 7 m footprint on two floors (42 m² of new floor space). That's based on £2,050–£2,750 per m² including VAT for the West Midlands. Keep a contingency of around 10% for things nobody can see until the ground is opened up.

Spec	Per m²	Typical project
Essential	£1,890–£2,530 per m²	£79,000–£106,500
Standard	£2,050–£2,750 per m²	£86,000–£115,500
Premium	£2,460–£3,300 per m²	£103,500–£138,500

Rules in England

In England, an annexe on two floors is assessed like any two-storey extension: at the rear it 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, but at the side it needs planning permission, costing £548 (or £575 for applications made from 8 December 2026). Councils often add a condition that the annexe stays ancillary to the main house and is not let separately.

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.

The Party Wall etc. Act 1996 applies, so notices may be needed for work on or near a shared wall or boundary.

Getting the design right

Ground-floor living for the future

Many annexes are planned so the occupant could live on the ground floor if stairs become difficult. A ground-floor bedroom space, a level-access shower and wider doorways cost little at the design stage and are expensive to add later.

Fire separation and escape

A kitchenette in an annexe and a bedroom above need safe escape and suitable separation from the main house. Building control checks the escape windows, smoke alarms and the door between the two parts.

How we work in Warwickshire

Measure and listen
A visit to Warwickshire to understand how you live in the house now and what the extra rooms need to do, plus a first look at the structure.
Drawings and permission
Our designers produce plans and elevations, then we take care of planning or permitted development checks with the council covering Warwickshire.
Engineer it
Foundations sized for two floors, steels for any openings, and building control approval, all before anyone starts on site.
On site
One project lead runs the job, keeps you updated and arranges inspections at each stage until completion.

Towns we cover in Warwickshire

Two-storey annexe extensions in Warwickshire: questions

How much does a two-storey annexe extension cost in Warwickshire?

In the West Midlands our guide is £2,050–£2,750 per m² including VAT, so about £86,000–£115,500 (plus kitchenette and shower room fittings, priced to your choice) for a 3 m × 7 m footprint on two floors (42 m² of new floor space). Essential and Premium specs move that by roughly 8% down or 20% up.

Does a two-storey annexe need planning permission?

It depends on where it goes and your nation. In England, a rear annexe extension can be permitted development within the 3 m and 7 m limits, but a side one always needs planning permission. If the annexe could work as a separate home, the council may treat it as a new dwelling, which needs full planning permission.

Can I rent out an annexe later?

Not always. Many annexe permissions include a condition that it is only used by members of the household, so renting it out may need a fresh planning application. If you think you might want to let it, tell us at the start so we can explain the options.

Can an annexe be designed for someone with limited mobility?

Yes. We can plan a ground-floor bedroom space, a level-access shower, wider doorways, lever handles and space for a stairlift later. These features are much cheaper to build in at the start than to add afterwards, and they keep the annexe useful as needs change.

Will I need planning permission in Warwickshire?

Warwickshire is in England. Planning permission is needed: in England, permitted development only allows single-storey extensions to the side.

Neighbouring areas

All extension services in Warwickshire · About two-storey annexe extensions