Extension plans and drawings in Northamptonshire
We prepare extension plans and drawings for homes across Northamptonshire, 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 covered9
- Site visitFree, no obligation
Towns in Northamptonshire
Working in Northamptonshire
Towns we cover in Northamptonshire include Northampton, Corby, Kettering, Wellingborough, Rushden, Daventry, Market Harborough, Towcester. The East Midlands has plenty of inter-war and post-war semis and detached houses with room to extend, alongside Victorian terraces in the towns.
Fees in Northamptonshire
These are guide fees for Northamptonshire, adjusted for East Midlands (×0.95) and including VAT. Council application and inspection fees are paid separately.
| 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.
Do I need planning permission in Northamptonshire?
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.
In a conservation area, national park, National Landscape, the Broads or a World Heritage Site the permitted development limits are tighter (no side or two-storey extensions without an application). Listed homes need listed building consent, and if permitted development rights have been removed, any extension needs an application.
Building over or within 3 m of a public sewer needs the water company's consent, usually through a build-over agreement, before the foundations go in.
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.
Applications are decided by the local planning authority (your district, borough or unitary council).
When it helps
- Anyone who wants fixed designs before getting build prices
- Projects that need a planning application or other approval
- Homeowners at the very start of a project
How the project works
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 Northamptonshire home, measure up, talk through what you want and check the planning position.
Design and approvals
Drawings are prepared and agreed with you, then submitted for the right planning route and building regulations approval.
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 Northamptonshire
Will my neighbours in Northamptonshire 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 building regulations approval in Northamptonshire?
Yes. Almost every extension needs it, whatever the planning route. We prepare the drawings and book the inspections.
Who do I contract with in Northamptonshire?
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 use your drawings with another builder?
Yes. Once paid for, the drawings are yours to use for your project.
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.
Book a free site visit in Northamptonshire
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.