Part single, part two-storey extensions in Kirkby-in-Ashfield
Adding a part single, part two-storey extension in Kirkby-in-Ashfield 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 Kirkby-in-Ashfield at a glance.
- Postcode districts
- NG17
- County / area
- Nottinghamshire, England
- Price region
- East Midlands
- Guide price
- £70,500–£97,000 (£1,960–£2,700 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
- Sutton-in-Ashfield (1.9 miles), Mansfield (2.9 miles), Pinxton (3.1 miles)
- Distance to Nottingham
- about 10.8 miles
- First visit
- Free, no obligation
About a part single, part two-storey extension
A part single, part two-storey extension is an extension where the ground floor is wider or deeper than the floor above, so only part of it rises to two storeys. It usually gives a large kitchen or living area with roof lights below and one bedroom or bathroom above. It is often a good way to add space while limiting the effect on neighbours.
Around Kirkby-in-Ashfield we also work in Sutton-in-Ashfield, Mansfield and Pinxton, and across the rest of Nottinghamshire. Postcode district in and near Kirkby-in-Ashfield: NG17.
What it costs in Kirkby-in-Ashfield
Most of the cost of a part single, part two-storey extension is set by its size and specification. For Kirkby-in-Ashfield and the rest of the East Midlands, our guide is £1,960–£2,700 per m² including VAT, so about £70,500–£97,000 for a 6 m × 4 m ground floor and a first floor over half of it (36 m² in total). The fastest way to a firmer number is a free site visit, after which we price the design stage in writing.
| Spec | Per m² | A 6 m × 4 m ground floor and a first floor over half of it (36 m² in total) |
|---|---|---|
| Essential | £1,800–£2,480 per m² | £65,000–£89,500 |
| Standard | £1,960–£2,700 per m² | £70,500–£97,000 |
| Premium | £2,350–£3,230 per m² | £84,500–£116,500 |
Planning and building regulations in Kirkby-in-Ashfield
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 Kirkby-in-Ashfield homes
The roof junction
Where the single-storey roof meets the two-storey wall you need a sound weathering detail, usually a lead or similar flashing, and enough height for roof lights or a lantern. We set the roof falls and the upstairs window sill heights together so they do not clash.
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
Free site visit
We visit your home in Kirkby-in-Ashfield, look at the structure, access and boundaries, and talk through what you want the new rooms to do.
Drawings, then consent
We draw the scheme, check it against the rules in England, and take it through the right consent with the council.
Detail and price
Construction drawings, engineer's calculations and building control sign-off, then a written fixed price for the build.
Finish and certify
Second fix, plastering and making good, then building control's final inspection and the completion paperwork.
Questions about part single, part two-storey extensions in Kirkby-in-Ashfield
Do I need planning permission for a part single, part two-storey extension in Kirkby-in-Ashfield?
Kirkby-in-Ashfield 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.
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.
Which postcodes do you cover around Kirkby-in-Ashfield?
We cover Kirkby-in-Ashfield (NG17) and nearby places including Sutton-in-Ashfield, Mansfield and Pinxton, plus the rest of Nottinghamshire. The first site visit is free.
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.
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
Close to Kirkby-in-Ashfield? We work across the area, including:
Other extensions in Kirkby-in-Ashfield
- Rear
- Side
- Wraparound
- Over a garage
- First floor
- Semi-detached
- Detached
- Kitchen and bedrooms
- Bedroom and en-suite
All two-storey extension services in Kirkby-in-Ashfield · Part single, part two-storey extensions across Nottinghamshire
Ready to talk it through? Call us or send the form and we'll arrange a visit to your home in Kirkby-in-Ashfield.