Covering Harlow
Alongside Harlow, we also cover Hoddesdon, Bishop's Stortford (7 miles to the north) and Waltham Abbey.
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 does a double-storey extension involve?
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.
- Structural engineer’s design and calculations
- Windows, insulation, plastering, electrics and plumbing
- Joining the new first floor to the existing landing
What is the guide price for a double-storey extension in Harlow?
What double-storey extensions typically cost. These are guide ranges; the written quote for your house replaces them.
| 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 Harlow?
Projects in England go through two separate checks. Planning (or confirmation that the work is permitted development) comes from the district, borough or unitary council, and building regulations approval comes from the council’s building control team or a registered building control approver. Where work touches a shared wall or digs near a neighbour’s foundations, the Party Wall etc. Act 1996 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 affect a double-storey extension?
- 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.
- Build and hand over. Our teams build to the programme, building control inspects, and you get the completion paperwork at the end.
Questions about a double-storey extension in Harlow
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.
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 Harlow 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.
Other towns nearby
- Double-storey extensions in Hoddesdon
- Double-storey extensions in Bishop's Stortford
- Double-storey extensions in Waltham Abbey
- Double-storey extensions in Cheshunt
Learn more about double-storey extensions, or see every project we cover in Harlow.

