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 Wisbech?
In Wisbech, a double-storey extension typically costs £1,750–£2,650 per m² of floor area (both floors), including VAT at 20% (standard rate). For a typical 36 m² project that is roughly £63,000–£95,500. That range is adjusted for the East of England, where domestic building work typically costs around 6% above the national average. Design, structural calculations and council fees are extra.
| Size or type | Guide range |
|---|---|
| Smaller project (25 m²) | £44,000–£66,000 |
| Typical project (36 m²) | £63,000–£95,500 |
| Larger project (50 m²) | £87,500–£132,500 |
| Rate per m² | £1,750–£2,650 |
Your quote will depend mainly on:
- Scaffolding and access to the rear
- Steel beams where walls are opened up
- Roof design and how it joins the existing roof
- Total floor area across both floors
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 Wisbech?
The approval route for Wisbech 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.
Where work involves a shared wall, building on the boundary, or digging foundations within 3 metres of a neighbour’s building and deeper than its foundations (or within 6 metres for deeper work), the Party Wall etc. Act 1996 applies and notices must be served before work starts.
If the answer is not clear-cut, we can apply for formal confirmation before you commit to the build.
What we handle
On a typical double-storey extension we handle:
- Design drawings and planning application
- Electrics, heating, plumbing and plastering
- Structural engineer’s calculations
- Opening up at both levels with steel beams
- Foundations, drainage and scaffolding
- Windows, doors and staircase alterations
How long does it take?
Allow 14 to 20 weeks on site, after planning and building control approval. Allow time beforehand for drawings and approvals, usually 3 to 4 months.
Building in Wisbech
Across the East of England, 1930s and post-war semis, newer estates and rural cottages all feature, each with different extension and loft options.
Our Wisbech coverage includes postcode districts PE13, and we also work in nearby places such as March, King's Lynn and Spalding.
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
Drawings and written quote
We prepare the design and give you a written, itemised quote with inclusions and exclusions.
- 03
Approvals
Planning or permitted development confirmation, building regulations and any party wall matters.
- 04
Build and handover
Work follows the agreed programme, with inspections along the way and a completion certificate at the end.
Questions about double-storey extensions in Wisbech
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.
Who approves a double-storey extension in Wisbech?
Planning matters in Wisbech go to the council covering your address, and the work needs building control approval. We prepare and submit the applications for you.
How much does a double-storey extension cost in Wisbech?
In Wisbech, a double-storey extension typically costs £1,750–£2,650 per m² of floor area (both floors), including VAT at 20% (standard rate). A typical 36 m² project comes to roughly £63,000–£95,500. Your fixed price depends on the survey and drawings.
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.
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.
