Covering St Helens
Alongside St Helens, we also cover Prescot, Ashton-in-Makerfield (4 miles to the north-east) and Huyton.
Homes in the North West
The North West has long rows of Victorian terraced houses in its towns and cities, alongside inter-war semis and post-war estates, so rear extensions, dormer lofts and kitchen extensions are common projects.
What do you get with a garden annexe?
We design annexes as permanent buildings with proper foundations, insulation and services, and we prepare the planning case showing how the annexe will be used as part of the main home. Connections for water, drainage and power are planned from the start.
- Foundations and drainage connections
- Brick, block or timber-frame structure
- Accessible design options for older relatives
How much should I budget for a garden annexe?
What garden annexes typically cost. These are guide ranges; the written quote for your house replaces them.
| Garden annexes | Guide price incl. VAT |
|---|---|
| Standard specification | £2,400 to £2,900 per m² |
| Good specification | £2,900 to £3,400 per m² |
| High specification | £3,400 to £3,900 per m² |
Do you need permission for a garden annexe in St Helens?
English projects need planning clearance from the local council, building regulations sign-off from building control, and party wall notices where the work is on or near a shared boundary. We prepare and manage all three.
A self-contained annexe used for sleeping and living normally needs planning permission in England.
What can change the price or programme?
- The annexe normally has to remain part of the main household, not let as a separate home.
- A level threshold and wider doors make the annexe suitable for later life.
From first call to completion
- Send us the details. Give us a postcode, a rough idea of size and some photos, by phone, form or the guide price tool.
- We visit and measure. A surveyor checks the house, the boundaries and the ground, and discusses what is realistic.
- Design and fixed price. You get drawings and a written price for the agreed specification before anything is ordered.
- Construction and completion. One site lead co-ordinates every trade through to the building control certificate.
Garden annexes: common questions
How much does a garden annexe cost?
Around £2,400 to £3,900 per square metre including VAT, depending on finish and services.
How long does an annexe take to build?
About 14 to 24 weeks on site after approvals.
Can you visit a house in St Helens to quote?
Yes. After a short call we arrange a site visit to measure up and agree what the design needs to do, then send a written price.
Garden annexes in nearby towns
- Garden annexes in Prescot
- Garden annexes in Ashton-in-Makerfield
- Garden annexes in Huyton
- Garden annexes in Newton-le-Willows
Learn more about garden annexes, or see every project we cover in St Helens.

