Epsom · Surrey

Two-storey side extensions in Epsom

Our two-storey side extensions service in Epsom covers everything: measured survey, design, planning or permitted development checks, structural design, building control and the build itself.

Quick reference for homeowners in Epsom.

Postcode districts
KT18
County / area
Surrey, England
Price region
South East England
Guide price
£94,500–£127,000 (£2,260–£3,030 per m²)
Approval route
Planning permission is needed: in England, permitted development only allows single-storey extensions to the side.
Nearest towns
Ewell (1.6 miles), Ashtead (2 miles), Chessington (2.7 miles)
Distance to Woking
about 12.5 miles
First visit
Free, no obligation

About a two-storey side extension

A two-storey side extension is a new two-floor addition built into the space beside your house, often over a driveway or side passage. It typically adds one or two bedrooms upstairs and a utility, study or larger kitchen below, without giving up rear garden.

Around Epsom we also work in Ewell, Ashtead and Chessington, and across the rest of Surrey. Postcode district in and near Epsom: KT18.

What it costs in Epsom

For budgeting in Epsom, allow around £94,500–£127,000 for a two-storey side extension with a 3 m × 7 m footprint on two floors (42 m² of new floor space). That's based on £2,260–£3,030 per m² including VAT for South East England. Steelwork for wide openings is the item most likely to move the figure; we'll know once the engineer has designed it.

SpecPer m²A 3 m × 7 m footprint on two floors (42 m² of new floor space)
Essential£2,070–£2,780 per m²£87,000–£117,000
Standard£2,260–£3,030 per m²£94,500–£127,000
Premium£2,710–£3,630 per m²£113,500–£152,500

Planning and building regulations in Epsom

In England, a two-storey side extension always needs householder planning permission, because permitted development only allows single-storey extensions beyond a side wall. The fee is £548 (or £575 for applications made from 8 December 2026), and councils should decide within 8 weeks of validation. Expect them to look at set-back, roof height, gaps to the boundary and the effect on neighbours.

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.

Design points for Epsom homes

Matching the ridge and roof

A hipped house usually needs a hipped extension roof, and a gabled house a gable. Matching the pitch, tiles, ridge detail and brick bond is what makes a side extension look original rather than added, and councils look closely at it on a front-facing addition.

Avoiding a terracing effect

Where semi-detached houses sit close together, side extensions on neighbouring houses can join up and turn a row of pairs into a terrace. Many councils ask for a gap to the boundary at first floor to stop this, so we check local guidance before fixing the width.

How we'd run your project

  1. Start at your house

    We come to your home in Epsom, measure up, check the ground floor walls and roof structure, and note anything near the boundaries.

  2. Drawings, then consent

    We draw the scheme, check it against the rules in England, and take it through the right consent with the council.

  3. Technical design

    We prepare the building regulations drawings, structural calculations and specification so the build price can be fixed.

  4. On site

    One project lead runs the job, keeps you updated and arranges inspections at each stage until completion.

Questions about two-storey side extensions in Epsom

How long does a two-storey side extension take?

Allow 4 to 8 weeks for survey and design, then the approval period (councils should decide householder applications within 8 weeks of validation), then 4 to 8 weeks of technical design, which can overlap. The build itself usually takes 14 to 20 weeks, longer for large or complex designs.

Do I need planning permission for a two-storey side extension in Epsom?

Epsom is in England, so England planning rules apply. Planning permission is needed: in England, permitted development only allows single-storey extensions to the side. If in doubt, a lawful development certificate or a planning application gives you certainty before you build.

Which postcodes do you cover around Epsom?

We cover Epsom (KT18) and nearby places including Ewell, Ashtead and Chessington, plus the rest of Surrey. The first site visit is free.

How much does a two-storey side extension cost in Epsom?

Our guide for South East England, which covers Epsom, is £2,260–£3,030 per m² including VAT. A typical project with a 3 m × 7 m footprint on two floors (42 m² of new floor space) comes to about £94,500–£127,000. Design and approval fees are extra, and we fix the build price in writing once the design is agreed.

Can I build a two-storey side extension over my driveway?

Yes, if the drive is wide enough for a useful room and the council accepts the design. You may lose off-road parking, which some councils weigh up, and the foundations need to suit the ground below. We check parking, drains and meter positions at the free site visit before any drawings are prepared.

Nearby

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