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 Ipswich?
In Ipswich, 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. Prices across the East of England are typically 6% above the UK average for this kind of work, which is reflected in the range for Ipswich. 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:
- Steel beams where walls are opened up
- Brick matching and external finishes
- Total floor area across both floors
- Bathrooms or en-suites on the first floor
Your exact price depends on the survey and drawings. The guide price tool gives a quick range in the meantime.
Do you need planning permission for a double-storey extension in Ipswich?
The approval route for Ipswich 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.
At the survey we check your house’s planning history and any restrictions, and tell you which route applies.
What we handle
The work we manage on a double-storey extension:
- Windows, doors and staircase alterations
- Brick or block walls, floors and a roof tied into the house
- Electrics, heating, plumbing and plastering
- Foundations, drainage and scaffolding
- Structural engineer’s calculations
- Design drawings and planning application
How long does it take?
Expect 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 Ipswich
Many towns in the East of England have estates built since the 1970s, where garage conversions and rear extensions are popular.
We work across Ipswich and neighbouring areas such as Harwich, Felixstowe and Stowmarket. Postcodes we cover in Ipswich include IP1, IP3 and IP4.
How it works
- 01
Visit and measured survey
A free visit to understand the project, check access and take measurements.
- 02
Design and fixed quote
Drawings, structural calculations and an itemised, fixed price for the agreed specification.
- 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 Ipswich
Does a double-storey extension need planning permission?
Usually. In England a two-storey rear extension can only be permitted development if it is no more than 3 metres deep and at least 7 metres from the rear boundary, and side extensions over one storey always need permission. In practice most are approved through a planning application.
What drawings do I need?
Planning drawings for the application, then more detailed building regulations drawings and structural calculations for building control. We prepare both.
How much does a double-storey extension cost in Ipswich?
In Ipswich, 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.
Do you build double-storey extensions in Ipswich?
Yes. We build double-storey extensions across Ipswich, including postcodes IP1, IP3 and IP4. Every project starts with a free home visit.
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.
