Part single, part two-storey extensions in Great Sankey
Adding a part single, part two-storey extension in Great Sankey 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 England.
Quick reference for homeowners in Great Sankey.
- Postcode districts
- WA5
- County / area
- Cheshire, England
- Price region
- North West England
- Guide price
- £68,500–£94,000 (£1,900–£2,610 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
- Warrington (2.5 miles), Newton-le-Willows (4.3 miles), Widnes (4.4 miles)
- Distance to Warrington
- about 2.5 miles
- First visit
- Free, no obligation
About a part single, part two-storey extension
A part single, part two-storey extension suits you if you want a generous ground floor but only need one extra room upstairs, or if a full two-storey design would affect a neighbour too much. You get design options that test where the two-storey part works best, the approvals your nation needs, structural design, building regulations approval and the build, carried out by vetted teams working under S&K.
Around Great Sankey we also work in Warrington, Newton-le-Willows and Widnes, and across the rest of Cheshire. Postcode district in and near Great Sankey: WA5.
What it costs in Great Sankey
In North West England, which includes Great Sankey, we'd expect a part single, part two-storey extension to cost around £68,500–£94,000 for a 6 m × 4 m ground floor and a first floor over half of it (36 m² in total), or £1,900–£2,610 per m² including VAT. We'll give you a written design-stage price first, then a fixed build price once the drawings are agreed.
| Spec | Per m² | A 6 m × 4 m ground floor and a first floor over half of it (36 m² in total) |
|---|---|---|
| Essential | £1,750–£2,400 per m² | £63,000–£86,500 |
| Standard | £1,900–£2,610 per m² | £68,500–£94,000 |
| Premium | £2,280–£3,130 per m² | £82,000–£113,000 |
Planning and building regulations in Great Sankey
In England, the extension can only be permitted development if it goes no more than 3 m beyond the original rear wall and stays at least 7 m from the rear boundary, with matching materials and roof pitch. We check the whole design against the rules, including the 50% garden coverage limit. If any part fails, or extends beyond a side wall on two floors, you need planning permission, costing £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 Great Sankey homes
Where to put the two-storey part
The two-storey section usually works best away from the closest neighbour, with the single-storey part on that boundary side. We test a few positions against neighbours' windows, the upstairs layout and the roof shape before choosing the one to take forward.
Structure at the step
The first-floor wall above often sits over the new open-plan space, so it needs a steel beam or frame to carry it. Loads come down at different points than in a full two-storey design, and the engineer sizes the foundations to suit each part.
How we'd run your project
Understand the brief
At your home in Great Sankey we agree what you need: bedroom count, bathroom, kitchen space, and how much garden you want to keep.
Plans, then approval
Measured survey, design, then the right approval route for your house. We explain each step before we take it.
Fixed price in writing
With approved drawings and calculations, we give you a fixed build price and a programme you can plan around.
Build and hand over
We manage the build from groundworks to decoration-ready finish and hand over with the completion paperwork.
Questions about part single, part two-storey extensions in Great Sankey
Do I need planning permission for a part single, part two-storey extension in Great Sankey?
Great Sankey is in England, so England planning rules apply. 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. If in doubt, a lawful development certificate or a planning application gives you certainty before you build.
Which postcodes do you cover around Great Sankey?
We cover Great Sankey (WA5) and nearby places including Warrington, Newton-le-Willows and Widnes, plus the rest of Cheshire. The first site visit is free.
How long does a part single, part two-storey 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 add roof lights to the single-storey part?
Yes. Roof lights or a lantern over the single-storey part are one of the main reasons to choose this design, as they light the middle of a deep kitchen. In England they count towards the Part L glazing allowance, normally 25% of the new floor area plus windows removed, so we balance them with the rear doors.
Can the single-storey part be deeper than the two-storey part?
With planning permission, yes, and that is often the point of the design: the ground floor projects further into the garden while the first floor stays back from neighbours. Under permitted development, the depth limits for extensions of more than one storey can apply to the whole extension, so we confirm which route applies before drawings are finalised.
Nearby
We also cover places near Great Sankey, including:
Other extensions in Great Sankey
- Rear
- Side
- Wraparound
- Over a garage
- First floor
- Semi-detached
- Detached
- Kitchen and bedrooms
- Bedroom and en-suite
All two-storey extension services in Great Sankey · Part single, part two-storey extensions across Cheshire
Tell us about your house in Great Sankey and we'll call you back to arrange a free, no-obligation visit.