Two-storey front extensions in Hertfordshire

Hertfordshire at a glance

Nation: England
Price region: East of England
Postcode areas: AL, CM, EN, HP, SG, WD
Towns covered: 33 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 Hertfordshire include Watford (WD1), Hemel Hempstead (HP1), Stevenage (SG1), St Albans (AL1), Welwyn Garden City (AL6) and Cheshunt (EN7). If yours isn't listed, we still cover it.

Guide price in the East of England

Guide prices for two-storey front extensions in the East of England are around £2,270–£3,090 per m² of new floor space, including VAT. For a typical project with a 3 m × 2 m footprint on two floors (12 m² of new floor space), that's roughly £27,000–£37,000. Keep a contingency of around 10% for things nobody can see until the ground is opened up.

Spec	Per m²	Typical project
Essential	£2,080–£2,840 per m²	£25,000–£34,000
Standard	£2,270–£3,090 per m²	£27,000–£37,000
Premium	£2,720–£3,710 per m²	£32,500–£44,500

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

Parking and access

Building forward can reduce off-road parking and the space for bins and meters. Councils may weigh up parking, so we check the drive will still work, along with the routes for gas, electricity and water supplies that often enter at the front.

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.

How we work in Hertfordshire

Free site visit
We visit your home in Hertfordshire, look at the structure, access and boundaries, and talk through what you want the new rooms to do.
Drawings and permission
Our designers produce plans and elevations, then we take care of planning or permitted development checks with the council covering Hertfordshire.
Price it properly
Once the engineer's calculations are in, we fix the build price in writing, with a clear list of what's included.
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 Hertfordshire

Two-storey front extensions in Hertfordshire: questions

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

In the East of England our guide is £2,270–£3,090 per m² including VAT, so about £27,000–£37,000 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.

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 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.

Does a front extension affect my parking?

It can. If it is built over part of the drive you may lose a parking space, and some councils consider whether enough off-road parking remains. We measure the drive at the survey and show on the drawings how cars, bins and meters will fit after the work.

Will I need planning permission in Hertfordshire?

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

Neighbouring areas

All extension services in Hertfordshire · About two-storey front extensions