Design and build two-storey extensions in Surrey

Surrey at a glance

Nation: England
Price region: South East England
Postcode areas: CR, GU, KT, RH, SM, TW
Towns covered: 35 listed below, plus surrounding villages
Site visits: Free, no obligation

What a design and build project involves

This service suits you if you want one team accountable from the first visit to the completion certificate. We manage the design, approvals and build, and the work is carried out by vetted teams working under S&K. Because the same team designs and builds, costs are checked as the design develops. Every project starts with a free site visit.

The main places we list in Surrey are Woking (GU21), Guildford (GU1), Esher (KT10), Redhill (RH1), Staines (TW18) and Banstead (KT20). We cover the villages in between too.

Fees

The design stage is priced in writing before it starts, and the build is a fixed price in writing once the design is agreed.

Rules in England

In England, design and build covers the permitted development check or planning application (£548 (or £575 for applications made from 8 December 2026)), building regulations approval from council building control or a registered approver, Party Wall Act notices where needed, and the Building Safety Act dutyholder roles. We programme them so they overlap where possible.

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

How the stages work

We start with a free site visit, then a design stage priced in writing before it begins. That covers the survey, design, approvals, structural design and building regulations. Once the design is agreed, the build price is fixed in writing before work starts.

Responsibility for the rules

In England, where more than one contractor is involved, a principal designer and principal contractor must be appointed. On design and build projects we take on these duties, so you are not left holding responsibilities you may not know you had.

How we work in Surrey

Measure and listen
A visit to Surrey 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 Surrey and deal with any questions from the planning officer.
Detail and price
Construction drawings, engineer's calculations and building control sign-off, then a written fixed price for the build.
Finish and certify
Second fix, plastering and making good, then building control's final inspection and the completion paperwork.

Towns we cover in Surrey

Design and build two-storey extensions in Surrey: questions

Do I have to use you for the build if I pay for the design stage?

No. The design stage is priced separately, so you can take the approved drawings to other builders if you choose. Most people who use design and build carry on to the build, because the design has been costed as it developed.

Who builds my extension?

Your extension is built by vetted teams working under S&K, with the project managed by us from design to completion. You have one point of contact throughout, and the same team that prepared the design is responsible for the build.

What is the difference between design and build and using an architect?

With an architect, you appoint them for the design and approvals, then find and manage a builder separately. With design and build, one team does both, so cost, buildability and approvals are considered together and there is one point of contact. Some people still prefer to hire an architect separately.

Neighbouring areas

All extension services in Surrey · About design and build two-storey extensions