Part single, part two-storey extensions in Ilkeston
Adding a part single, part two-storey extension in Ilkeston 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.
Useful details for planning a part single, part two-storey extension in Ilkeston.
- Postcode districts
- DE7
- County / area
- Derbyshire, 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
- Kimberley (2 miles), Eastwood (2.1 miles), Heanor (3.5 miles)
- Distance to Derby
- about 7.7 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.
We cover postcode district DE7 in and around Ilkeston, along with neighbouring Kimberley, Eastwood and Heanor.
What it costs in Ilkeston
Most of the cost of a part single, part two-storey extension is set by its size and specification. For Ilkeston 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). 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 | £1,800–£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 Ilkeston
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 Ilkeston homes
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.
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
Free site visit
We visit your home in Ilkeston, look at the structure, access and boundaries, and talk through what you want the new rooms to do.
Drawings and permission
Our designers produce plans and elevations, then we take care of planning or permitted development checks with the council covering Ilkeston.
Detail and price
Construction drawings, engineer's calculations and building control sign-off, then a written fixed price for the build.
Build and sign-off
Vetted teams working under S&K build the extension, and we arrange the building control completion certificate at the end.
Questions about part single, part two-storey extensions in Ilkeston
How much does a part single, part two-storey extension cost in Ilkeston?
Our guide for the East Midlands, which covers Ilkeston, is £1,960–£2,700 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 £70,500–£97,000. Design and approval fees are extra, and we fix the build price in writing once the design is agreed.
Do I need planning permission for a part single, part two-storey extension in Ilkeston?
Ilkeston 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 Ilkeston?
We cover Ilkeston (DE7) and nearby places including Kimberley, Eastwood and Heanor, plus the rest of Derbyshire. The first site visit is free.
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.
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.
Nearby
Close to Ilkeston? We work across the area, including:
Other extensions in Ilkeston
- Rear
- Side
- Wraparound
- Over a garage
- First floor
- Semi-detached
- Detached
- Kitchen and bedrooms
- Bedroom and en-suite
All two-storey extension services in Ilkeston · Part single, part two-storey extensions across Derbyshire
Tell us about your house in Ilkeston and we'll call you back to arrange a free, no-obligation visit.