Extension plans and drawings in Merseyside
We prepare extension plans and drawings for homes across Merseyside, on their own or as the first stage of a full design and build project.
- Guide priceFrom £1,100 inc VAT
- PlanningWe find the right route for you
- Towns covered17
- Site visitFree, no obligation
Towns in Merseyside
When it helps
- Anyone who wants fixed designs before getting build prices
- Homeowners at the very start of a project
- Projects that need a planning application or other approval
The most expensive changes are the ones made after the steel is ordered. A good design stage settles layout, heights, glazing and services on paper, so the build price is firm.
Will the council need to approve it?
In England the main routes are permitted development (ideally confirmed with a lawful development certificate, £274), larger home extension prior approval (£249, 42 days) and a householder planning application (£548, normally 8 weeks), with council fees as set from 1 April 2026.
Before any drawing is finalised we check whether the house is listed, in a conservation area or subject to an Article 4 direction.
Building regulations approval is separate from planning. In England you can use the council's building control team or a registered building control approver; a full plans application gets the drawings checked before work starts, and the inspector signs the work off with a completion certificate.
If the work involves a shared wall, building on the boundary, or digging foundations within 3 m (sometimes 6 m) of a neighbour's building, the Party Wall etc. Act 1996 applies and notice must be served before work starts: two months for work to a party wall, one month for new walls on the boundary and for excavations.
Applications are decided by the local planning authority (your district, borough or unitary council).
Local to Merseyside
Towns we cover in Merseyside include Liverpool, Birkenhead, St Helens, Southport, Wallasey, Bootle, Bebington, Huyton. Across the North West, terraced houses with small rear yards suit compact rear and side return extensions, while suburban semis have room for more.
Fees in Merseyside
Fees below are our Merseyside guide (×0.95, the North West England factor), including VAT. Council and building control fees are extra.
| Option | What it covers | Guide price |
|---|---|---|
| Essential | Measured survey and planning drawings | £1,100 – £2,100 |
| Standard | Planning drawings plus building regulations drawings | £2,050 – £3,650 |
| Premium | Full pack with structural calculations and 3D visuals | £3,200 – £5,250 |
Try the guide-price tool to see a range for your own size and finish.
Our process, step by step
Site visits are free and there is no obligation. Where drawings are needed, the design stage is priced in writing before it starts.
Free site visit
We visit your Merseyside home, measure up, talk through what you want and check the planning position.
Design and approvals
We draw the design, agree it with you and handle planning or permitted development checks and building regulations.
Fixed written price
The price is fixed in writing once the design is settled, with a clear programme and payment stages.
Build and sign-off
Work is carried out to the agreed programme, inspected by building control and signed off at the end.
Common questions in Merseyside
Who do I contract with in Merseyside?
Your contract is with S&K Property Investments and Improvement Ltd, which designs and manages the project and the build teams who carry it out.
Can I see a price before committing to anything?
Yes. The guide prices on this page are adjusted for Merseyside, and the guide-price tool gives a range for your own size. After the survey you get a written price before anything is agreed.
Will my neighbours in Merseyside be involved?
If a planning application or prior approval is needed, the council notifies neighbours. If the work is on or near a shared boundary, party wall notices may also be needed.
Do I need an architect?
Not necessarily. For most extensions an experienced designer or architectural technologist is enough. For listed buildings or complex sites an architect’s input can help.
How much do extension plans cost?
Our design packs range from about £1,100 to £5,250 including VAT, from planning drawings only to a full pack with building regulations drawings, structural calculations and 3D views. Council fees are separate.
Book a free site visit in Merseyside
We will measure up, check the planning position and give you honest guide figures.
- Free, no-obligation site visit
- Planning route checked before you spend on drawings
- Written price once the design is agreed
- Building control sign-off at the end
Prefer to talk? Call 0800 088 6341 or .
Book a free site visit
Tell us a little about the project and we will arrange a time.