A double-storey extension adds two floors of new space to your house in one build, typically a larger kitchen or living room downstairs with an extra bedroom, bathroom or en-suite above, sharing one set of foundations and one roof.
If you are planning a double-storey extension anywhere in Derbyshire, including Derby, Chesterfield, Long Eaton and Ilkeston, we can visit, measure up and talk through the options. The planning and building regulations we work to are those for England, and we check them for your address before quoting. Prices remain guide figures for the East Midlands, at £58,000–£115,000 including VAT, until the survey is done.
- Guide price
- £58,000–£115,000 inc VAT
- Time on site
- 14–22 weeks on site
- Planning rules
- England
- Price level
- About 4% below the national guide
- Towns listed
- 12
- Survey
- Free, with a written quote
How much does a double-storey extension cost in Derbyshire?
Below is a breakdown of typical costs for a double-storey extension in Derbyshire. Because rates in the East Midlands are about 4% below the national guide, the overall guide comes to £58,000–£115,000, including VAT. Size, materials and access move the figure, and a free-of-charge survey settles it.
| Type of job | What it usually involves | Guide in Derbyshire |
|---|---|---|
| Small (15–20m² total) | A compact rear or side extension adding a small room on each floor. | £38,500–£62,000 |
| Typical (30–40m² total) | A larger kitchen or living room below with a double bedroom or en-suite above. | £58,000–£115,000 |
| Large (50m² plus total) | Wide or deep extensions, often with a new bathroom, steelwork and high-spec glazing. | £96,000–£173,000 |
The main things that change the figure:
- Combined floor area across both storeys
- How the new roof joins the existing roof
- Bathrooms, en-suites and plumbing on the upper floor
- Scaffolding duration, access and the level of finishes
Scope of the work
- Groundworks, foundations and below-ground drainage
- Insulated cavity walls with brick or render to match the house
- First-floor joists, stud walls and new openings upstairs
- Scaffolding for the full build, erected and inspected
- Electrics, plumbing and heating by qualified trades, with certificates
- Windows, external doors, plastering and internal doors
Homes in Derbyshire
Derby has wide areas of Victorian red-brick terraces and interwar semis, while Peak District villages use gritstone and limestone under stone-slate or Welsh slate roofs. Former mining towns in the north-east of the county have brick terraces and post-war housing built for mining communities, and modern estates have grown around Derby, Chesterfield and the M1 corridor.
Brick terraces frequently suit loft conversions and rear extensions, and many need repointing. Stone properties in the Peak may call for lime work and planning-sensitive windows, while interwar and estate homes commonly take side extensions and garage conversions.
The High Peak gets heavy rain, snow and frequent frost, while the lower Trent valley is milder; old mine workings can also affect ground conditions in places.
Planning and building rules in Derbyshire
England, Wales, Scotland and Northern Ireland each handle planning a little differently. Derbyshire comes under England, covered below, and we raise any questions with the council before your quote is finalised.
In England, a two-storey rear extension can only be permitted development if it is no more than 3 m deep, at least 7 m from the rear boundary and finished to match the house. Most double-storey and all two-storey side extensions need full planning permission.
Building Regulations approval is needed, with structural calculations for beams, foundations and the roof. The Party Wall etc. Act 1996 often applies on semi-detached and terraced houses.
Rules change and every property is different, so we check the planning history and constraints for your address before we quote.
How does the job run?
A visit to your home
Book a visit and we'll come to you. The survey covers measurements, the state of what's there now and any obvious constraints, so the price that follows is based on your actual home, not an average.
Written quote
The quote arrives in writing, not over the phone. It covers the full scope, the finishes you've chosen, any exclusions and the payment schedule, with a fixed price tied to that specification.
Dates and permissions
Once you accept, we agree start dates, order materials and deal with any planning, building control or neighbour notices the job needs. You'll know who is coming and when before work begins.
Build and hand over
On site, the agreed plan is followed and any change is put in writing first. At completion we do a final clean, go through the snagging list with you and leave you with the relevant documents.
How we work
Questions about a double-storey extension in Derbyshire
How much does a double-storey extension cost?
A typical double-storey extension of 30–40m² across both floors costs £58,000–£115,000, built to a plastered finish. As a rough guide, allow around £1,400–£2,600 per square metre plus fixed costs for groundworks, scaffolding and fees. The second storey usually costs less per square metre than the first, because foundations and roof are shared. Bathrooms upstairs and a complex roof add most. We confirm a fixed price after the survey.
Do you cover Derby, Chesterfield and Long Eaton?
Yes. As well as Derbyshire, we cover Derby, Chesterfield and Long Eaton and the rest of Derbyshire. Our coverage is UK-wide, so the process is the same wherever you are: a free site survey, a quote in writing that fixes the price for the agreed scope, and one point of contact while the work is planned and carried out.
Who do I deal with during the job?
One point of contact manages your project from survey to handover. They schedule the trades working under our contract, keep you updated on progress, and are the person to call with any question. You don't need to coordinate builders, electricians or decorators separately, because that is part of what we do.
Will the extension affect my neighbours?
A double-storey extension can affect neighbours' light, outlook and privacy, which is why planning departments look closely at height, depth and window positions. Side windows facing neighbours often need obscure glass. Work near a shared wall may also need party wall notices; the Party Wall etc. Act 1996 applies in England and Wales only. We talk through these points early so the design is realistic.
Can the new upstairs room have its own bathroom?
A new upstairs room can usually have an en-suite, provided waste pipes can reach the soil stack or a new one can be installed. Running the waste pipe to the right falls is the main design question, and a pumped system is an option where gravity will not work. We plan bathroom positions at the design stage so pipes, ventilation and insulation are built in rather than added later.
Towns in Derbyshire
Looking for a double-storey extension somewhere in Derbyshire? Start with the towns below; each links to a page with pricing for your region and coverage details.