What is a double-storey extension?
A double-storey extension (also called a two-storey extension) adds rooms on both the ground and first floor in one build. It typically gives a larger kitchen or living space downstairs and an extra bedroom or bathroom above.
How much does a double-storey extension cost in Chesterfield?
In Chesterfield, a double-storey extension typically costs £1,550–£2,400 per m² of floor area (both floors), including VAT at 20% (standard rate). For a typical 36 m² project that is roughly £56,000–£86,500. Building costs in the East Midlands run about 5% below the UK average, and the figures for Chesterfield are adjusted to reflect that. Design, structural calculations and council fees are extra.
| Size or type | Guide range |
|---|---|
| Smaller project (25 m²) | £39,000–£60,000 |
| Typical project (36 m²) | £56,000–£86,500 |
| Larger project (50 m²) | £77,500–£120,000 |
| Rate per m² | £1,550–£2,400 |
The main things that change the cost:
- Brick matching and external finishes
- Bathrooms or en-suites on the first floor
- Scaffolding and access to the rear
- Roof design and how it joins the existing roof
For a figure based on your own measurements, try the guide price tool, then book a free home visit for a fixed quote.
Do you need planning permission for a double-storey extension in Chesterfield?
The approval route for Chesterfield is set by planning law in England. In England an extension of more than one storey can only be permitted development at the rear, no more than 3 metres deep and at least 7 metres from the rear boundary, with matching materials and any upper side windows obscure-glazed. Most double-storey extensions therefore go through a householder planning application.
Building regulations approval comes from the council’s building control service or a registered building control approver. The work is inspected at key stages, such as foundations, drainage and insulation, and a completion certificate is issued at the end.
Our first visit includes a check of your planning history, so you know the route before paying for drawings.
What we handle
The work we manage on a double-storey extension:
- Opening up at both levels with steel beams
- Windows, doors and staircase alterations
- Foundations, drainage and scaffolding
- Building control sign-off
- Brick or block walls, floors and a roof tied into the house
- Structural engineer’s calculations
How long does it take?
Allow 14 to 20 weeks on site, after planning and building control approval. Design and approvals come first and typically take 3 to 4 months, depending on the approval route.
Building in Chesterfield
In the East Midlands, many estates built since the 1960s have integral garages that convert well into a study or bedroom.
Chesterfield sits in Derbyshire, about 9 miles south of Sheffield. We cover the whole of Chesterfield, including postcodes S40 and S49.
How it works
- 01
Free visit
We look at the property, talk through what you want and measure up. There is no charge and no obligation.
- 02
Design and pricing
Design options, then a fixed quote based on the chosen drawings and specification.
- 03
Approvals
Planning or permitted development confirmation, building regulations and any party wall matters.
- 04
Construction and completion
We build, put right any snags and hand over the building control certificate.
Questions about double-storey extensions in Chesterfield
How much does a double-storey extension cost in Chesterfield?
In Chesterfield, a double-storey extension typically costs £1,550–£2,400 per m² of floor area (both floors), including VAT at 20% (standard rate). A typical 36 m² project comes to roughly £56,000–£86,500. Your fixed price depends on the survey and drawings.
How long does a double-storey extension take in Chesterfield?
Typically 14 to 20 weeks on site, after planning and building control approval. Design and approvals beforehand usually take 3 to 4 months.
How close can it be to my neighbour?
Councils look at loss of light and outlook for neighbours. Many apply a 45-degree guideline from the nearest neighbouring window. We design to the council’s published guidance to give the application the best chance.
Will the first floor need a new staircase?
Not normally. The new rooms are reached from the existing landing, though a doorway or short corridor may need to be formed.
Can I live at home during the work?
Most families stay put. The shell is built first and the house is opened up late in the job, so disruption inside is limited to a few weeks.