Extension plans and drawings in Northampton
For Northampton homeowners we handle extension plans and drawings, with fees agreed in writing before any work starts.
- Guide price in NorthamptonFrom £1,100 inc VAT
- PlanningWe find the right route for you
- Timescale2–6 weeks for drawings
- Postcode districtsNN1, NN2, NN3, NN4, NN5
Design and approval fees for Northampton
Guide fees for Northampton including VAT, using our East Midlands factor of ×0.95. Council and building control charges are not included.
| 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 |
Want a range for your exact size? The guide-price tool takes about a minute.
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.
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.
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.
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.
Applications are decided by the local planning authority (your district, borough or unitary council).
What we take care of
- Measured survey of the house and garden
- Building regulations drawings and specification
- Two or three layout options to compare
- Structural calculations from an engineer (full pack)
- 3D views to check the look and the light (full pack)
- Planning drawings: existing and proposed plans and elevations, site and location plans
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.
Local to Northampton
Across NN1, NN2, NN3, NN4, NN5, NN7, we can visit, measure and advise. Neighbouring towns we cover include Wellingborough (9 miles), Towcester (10 miles), Daventry (12 miles), Rushden (12 miles).
Just over the Buckinghamshire border, Milton Keynes is about 15 miles away. Homes across the East Midlands often have usable side land or a driveway beside the house, which opens up side and wraparound options.
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
A designer visits, takes measurements and photos, and discusses layouts, budget and timing with you.
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
The build is managed from start to finish, inspected at each stage and signed off on completion.
Common questions in Northampton
Do you cover all of Northampton?
Yes. We cover Northampton and the surrounding parts of Northamptonshire. Site visits are free and there is no obligation.
Do I need building regulations approval in Northampton?
Yes. Almost every extension needs it, whatever the planning route. We prepare the drawings and book the inspections.
Will my neighbours in Northampton 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 Northampton
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.