Two-storey side extensions in Royston (Cambridgeshire)

The basics for Royston (Cambridgeshire) at a glance.

Postcode districts: SG8
County / area: Cambridgeshire, England
Price region: East of England
Guide price: £88,500–£119,000 (£2,110–£2,830 per m²)
Approval route: Planning permission is needed: in England, permitted development only allows single-storey extensions to the side.
Nearest towns: Baldock (8.1 miles), Letchworth Garden City (9.8 miles), Biggleswade (10.6 miles)
Distance to Peterborough: about 37.5 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.

Royston (Cambridgeshire) sits about 37.5 miles from Peterborough. Closer to home, Baldock is 8.1 miles away and Letchworth Garden City 9.8 miles.

What it costs in Royston (Cambridgeshire)

Expect a two-storey side extension in Royston (Cambridgeshire) to land somewhere around £88,500–£119,000 for a 3 m × 7 m footprint on two floors (42 m² of new floor space). Our East of England guide rate is £2,110–£2,830 per m², including VAT. Keep a contingency of around 10% for things nobody can see until the ground is opened up.

Spec	Per m²	A 3 m × 7 m footprint on two floors (42 m² of new floor space)
Essential	£1,940–£2,610 per m²	£81,500–£109,500
Standard	£2,110–£2,830 per m²	£88,500–£119,000
Premium	£2,530–£3,400 per m²	£106,500–£143,000

Planning and building regulations in Royston (Cambridgeshire)

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 Royston (Cambridgeshire) homes

Set-down and set-back

Councils usually want a two-storey side extension to look subordinate to the house. Setting the front wall back from the main front and dropping the ridge slightly below the main roof helps it read as an addition, and is often expected in local design guidance.

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.

How we'd run your project

Measure and listen
A visit to Royston (Cambridgeshire) to understand how you live in the house now and what the extra rooms need to do, plus a first look at the structure.
Get it approved
Once you're happy with the design we submit it to the council for Royston (Cambridgeshire) and deal with any questions from the planning officer.
Technical design
We prepare the building regulations drawings, structural calculations and specification so the build price can be fixed.
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 Royston (Cambridgeshire)

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.

Who handles building regulations for a project in Royston (Cambridgeshire)?

We handle it as part of the project. What's needed in England: building regulations approval (full plans recommended) from the council or a registered building control approver, with a completion certificate at the end. We prepare the drawings and the engineer's calculations, book the inspections and pass you the completion paperwork at the end.

Which postcodes do you cover around Royston (Cambridgeshire)?

We cover Royston (Cambridgeshire) (SG8) and nearby places including Baldock, Letchworth Garden City and Biggleswade, plus the rest of Cambridgeshire. The first site visit is free.

How much does a two-storey side extension cost in Royston (Cambridgeshire)?

Our guide for the East of England, which covers Royston (Cambridgeshire), is £2,110–£2,830 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 £88,500–£119,000. 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

Other towns near Royston (Cambridgeshire):

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The quickest next step is a visit. We'll look at your house in Royston (Cambridgeshire) and give you an honest view of the options.