Covering Grays
Grays is about 19 miles south of Chelmsford. We also cover South Ockendon (3 miles to the north-west), Gravesend and Dartford.
Homes in the East of England
The East of England has a large stock of post-war and modern estate housing alongside period homes in market towns, which makes garage conversions, single-storey extensions and loft conversions popular.
What goes into 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.
- Measured survey, design and planning drawings
- Structural engineer’s design and calculations
- Windows, insulation, plastering, electrics and plumbing
How much does a double-storey extension cost in Grays?
Use these ranges to budget for double-storey extensions; the survey turns them into a fixed price for the agreed specification.
| 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 Grays?
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 should I think about before starting?
- Neighbours’ light is assessed using the 45-degree guide many councils use.
- The first-floor link can mean moving a bathroom or reshaping the landing.
What happens after I enquire?
- Start with a conversation. A short call or the online form is enough for us to understand what you want to build.
- 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.
- Build and hand over. Our teams build to the programme, building control inspects, and you get the completion paperwork at the end.
Double-storey extensions: common questions
Does a two-storey extension need planning permission?
Usually yes. In England some two-storey rear extensions are permitted development, but side extensions over one storey always need planning permission.
Will we need to move out?
Most people stay. The noisiest stage is when we break through into the existing first floor, which we plan for a short window.
Can you visit a house in Grays 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.
Also covering
- Double-storey extensions in South Ockendon
- Double-storey extensions in Gravesend
- Double-storey extensions in Dartford
- Double-storey extensions in Stanford-le-Hope
Learn more about double-storey extensions, or see every project we cover in Grays.

