Covering Havant
Alongside Havant, we also cover Waterlooville, Portsmouth (6 miles to the south-west) and Gosport.
Homes in the South East
The South East has a lot of 1930s and post-war semi-detached housing, well suited to rear extensions and hip-to-gable loft conversions, alongside period properties in conservation areas that need a more careful design.
What is a double-storey extension?
A double-storey extension adds new rooms on both the ground and first floor in one build, typically a larger kitchen or living space downstairs and an extra bedroom or bathroom above. Because the roof and foundations are shared, the cost per square metre is usually lower than a single-storey extension.
- Foundations, steelwork, brick and block walls, roof
- Windows, insulation, plastering, electrics and plumbing
- Joining the new first floor to the existing landing
How much does a double-storey extension cost in Havant?
Typical ranges for double-storey extensions. Ground conditions, access and specification move the final figure, which we fix in writing before work starts.
| Double-storey extensions | Guide price incl. VAT |
|---|---|
| Standard specification | £2,400 to £2,900 per m² |
| Good specification | £2,900 to £3,400 per m² |
| High specification | £3,400 to £3,850 per m² |
Do you need permission for a double-storey extension in Havant?
In England we deal with the council’s planning team for permission or a lawful development certificate, with building control (the council or a registered building control approver) for inspections, and with neighbours under the Party Wall etc. Act 1996 where it applies.
Two-storey rear extensions can sometimes be permitted development in England (no more than 3 m deep, at least 7 m from the rear boundary, roof pitch to match), but most two-storey and all two-storey side extensions need householder planning permission.
What can change the price or programme?
- Side extensions close to a boundary are often set back or stepped down so they do not create a terraced effect.
- Neighbours’ light is assessed using the 45-degree guide many councils use.
From first call to completion
- Tell us about the project. Call, use the guide price tool or send the form with a few photos and a postcode.
- We visit and measure. A surveyor checks the house, the boundaries and the ground, and discusses what is realistic.
- Drawings, approvals, written quote. We prepare the design, apply for the approvals it needs, and give you a fixed price in writing.
- We build it. Work follows an agreed programme, with inspections at each stage and a final sign-off.
What people ask before starting
How much does a two-storey extension cost?
Typically about £2,400 to £3,850 per square metre of new floor area including VAT. A 40 m² extension across two floors is often around £100,000 to £150,000 depending on specification.
Is a two-storey extension better value than a single-storey one?
Per square metre, usually yes, because the foundations and roof serve two floors of space.
Can you visit a house in Havant to quote?
Yes. After a short call we arrange a site visit to measure up and agree what the design needs to do, then send a written price.
Double-storey extensions in nearby towns
- Double-storey extensions in Waterlooville
- Double-storey extensions in Portsmouth
- Double-storey extensions in Gosport
- Double-storey extensions in Fareham
Learn more about double-storey extensions, or see every project we cover in Havant.

