Two-storey front extensions in Greater London

Greater London at a glance

Nation: England
Price region: London
Postcode areas: BR, CR, DA, E, EC, EN, HA, IG, KT, N, NW, RM, SE, SM, SW, TN, TW, UB, W, WC
Towns covered: 215 listed below, plus surrounding villages
Approval route: Planning permission is needed: nothing can go forward of the front wall under permitted development.
Site visits: Free, no obligation

What a two-storey front extension involves

A two-storey front extension is an addition built forward of the front wall of your house on both floors, often a deeper hall or study below and a larger bedroom above. Because it changes how the house looks from the street, it always needs planning permission in England and is judged closely on design. It suits houses set well back from the road.

Towns in Greater London include Brent (HA0), Islington (EC1V), Westminster (SW1), Bexley (DA5), Barking (E6) and Archway (N6). If yours isn't listed, we still cover it.

Guide price in London

In London, which includes Greater London, we'd expect a two-storey front extension to cost around £31,500–£43,000 for a 3 m × 2 m footprint on two floors (12 m² of new floor space), or £2,640–£3,600 per m² including VAT. These are guides, not quotes. Ground conditions, steelwork and access can move the figure either way.

Spec	Per m²	Typical project
Essential	£2,430–£3,310 per m²	£29,000–£39,500
Standard	£2,640–£3,600 per m²	£31,500–£43,000
Premium	£3,170–£4,320 per m²	£38,000–£52,000

Rules in England

In England, a two-storey front extension always needs householder planning permission, because permitted development does not allow any extension forward of the principal elevation. The fee is £548 (or £575 for applications made from 8 December 2026). Councils judge it mainly on design and the street scene, and should decide within 8 weeks of validation.

Approval in England: Householder planning application: £548 (or £575 for applications made from 8 December 2026). Lawful development certificate: £274 (about £288 for applications from 8 December 2026). Councils should decide householder applications within 8 weeks of validation.

Building regulations: Building regulations approval (full plans recommended) from the council or a registered building control approver, with a completion certificate at the end.

The Party Wall etc. Act 1996 applies, so notices may be needed for work on or near a shared wall or boundary.

Getting the design right

Daylight to existing rooms

A front extension can make the hall and front rooms darker, especially if it covers an existing window. We position new windows to keep the house bright, and check that the new front bedroom gets good daylight without overlooking houses opposite.

Roof and gable design

A front extension is the most visible part of the house, so the roof needs to look deliberate: a matching gable, a hipped bay or a porch roof below a first-floor bay. We match the pitch and materials and keep the ridge below the main roof.

How we work in Greater London

Visit and first ideas
One of our team visits your house in Greater London, checks the walls, roof and drains, and sketches out options with you.
Design and approvals
We draw the extension and check it against the rules for England, then apply for planning permission or a certificate of lawfulness, whichever fits.
Technical design
We prepare the building regulations drawings, structural calculations and specification so the build price can be fixed.
Build
Foundations, walls, floor, roof, windows, then first and second fix. We break through into the house as late as we can.

Towns we cover in Greater London

Two-storey front extensions in Greater London: questions

How much does a two-storey front extension cost in Greater London?

In London our guide is £2,640–£3,600 per m² including VAT, so about £31,500–£43,000 for a 3 m × 2 m footprint on two floors (12 m² of new floor space). Essential and Premium specs move that by roughly 8% down or 20% up.

How far forward can a front extension go?

There is no fixed figure, because a two-storey front extension needs planning permission and the council decides case by case. Many councils' design guides favour a shallow projection that keeps a clear front garden. Our guide prices assume a modest example with a 3 m × 2 m footprint on two floors (12 m² of new floor space).

Will the council approve a two-storey front extension?

It depends on the street. Councils are more cautious about front extensions than rear ones because they change the street scene. Approval is more likely where the house is set back, the projection is modest, the design echoes the original house and similar additions already exist nearby. We give you a frank view at the free site visit.

Can I combine a front extension with a porch?

Yes. A common approach is a two-storey bay or gable with a single-storey porch roof running across the front door. This gives a bigger hall and front bedroom while breaking up the mass of the front wall. Both parts are covered by the same planning application and building regulations approval.

Will I need planning permission in Greater London?

Greater London is in England. Planning permission is needed: nothing can go forward of the front wall under permitted development.

Neighbouring areas

All extension services in Greater London · About two-storey front extensions