Part single, part two-storey extensions in Nelson (Lancashire)
Adding a part single, part two-storey extension in Nelson (Lancashire) 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.
The basics for Nelson (Lancashire) at a glance.
- Postcode districts
- BB9
- County / area
- Lancashire, 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
- Brierfield (1.5 miles), Colne (2.1 miles), Burnley (2.7 miles)
- Distance to Preston
- about 21.2 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.
Nelson (Lancashire) sits about 21.2 miles from Preston. Closer to home, Brierfield is 1.5 miles away and Colne 2.1 miles.
What it costs in Nelson (Lancashire)
Guide prices for part single, part two-storey extensions in North West England are around £1,900–£2,610 per m² of new floor space, including VAT. For a typical project with a 6 m × 4 m ground floor and a first floor over half of it (36 m² in total), that's roughly £68,500–£94,000. Professional fees for drawings and the structural engineer are listed separately on our prices page.
| 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 Nelson (Lancashire)
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 Nelson (Lancashire) 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.
Light into the kitchen
The single-storey part is the place for roof lights or a lantern, which bring daylight deep into the plan. In England, glazing is normally limited to 25% of the new floor area plus any windows removed, unless calculations show the house still performs, so we plan the balance early.
How we'd run your project
Look at the house
We start in Nelson (Lancashire) 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.
Structure and building control
A structural engineer sizes the foundations and steels, and we get building regulations approval before work starts.
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 Nelson (Lancashire)
Which postcodes do you cover around Nelson (Lancashire)?
We cover Nelson (Lancashire) (BB9) and nearby places including Brierfield, Colne and Burnley, plus the rest of Lancashire. The first site visit is free.
Who handles building regulations for a project in Nelson (Lancashire)?
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.
How much does a part single, part two-storey extension cost in Nelson (Lancashire)?
Our guide for North West England, which covers Nelson (Lancashire), is £1,900–£2,610 per m² including VAT. A typical project with a 6 m × 4 m ground floor and a first floor over half of it (36 m² in total) comes to about £68,500–£94,000. Design and approval fees are extra, and we fix the build price in writing once the design is agreed.
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.
Which side should the two-storey part go on?
Usually the side furthest from the nearest neighbour's windows, so the single-storey part sits nearest them and keeps their light. Other factors are where the stairs land upstairs, which room needs the extra space and where drains run. We sketch options at the design stage and explain which is most likely to be approved.
Nearby
The same service in neighbouring towns:
Other extensions in Nelson (Lancashire)
- Rear
- Side
- Wraparound
- Over a garage
- First floor
- Semi-detached
- Detached
- Kitchen and bedrooms
- Bedroom and en-suite
All two-storey extension services in Nelson (Lancashire) · Part single, part two-storey extensions across Lancashire
The quickest next step is a visit. We'll look at your house in Nelson (Lancashire) and give you an honest view of the options.