Building regulations for extensions in Hampshire
We prepare building regulations for extensions for homes across Hampshire, on their own or as the first stage of a full design and build project.
- Guide priceFrom £1,000 inc VAT
- Approval routeFull plans or building notice
- Towns covered19
- Site visitFree, no obligation
Towns in Hampshire
What is included
- Structural calculations for beams, lintels and foundations
- Energy and glazing checks, including whole-house calculations if needed
- Completion certificate on sign-off
- Inspection bookings throughout the build
- Submission to the council or a registered building control approver
Design and approval fees for Hampshire
These are guide fees for Hampshire, adjusted for South East England (×1.12) and including VAT. Council application and inspection fees are paid separately.
| Option | What it covers | Guide price |
|---|---|---|
| Essential | Building regulations drawings for a simple single-storey extension | £1,000 – £2,050 |
| Standard | Drawings plus structural calculations | £1,450 – £2,950 |
| Premium | Complex or two-storey pack with energy calculations | £2,450 – £4,300 |
Our design fee only. Building control charges are set by your council (or, in England and Wales, a registered building control approver) and quoted separately.
For a figure based on your own dimensions, use our guide-price tool.
Local to Hampshire
Towns we cover in Hampshire include Southampton, Portsmouth, Basingstoke, Gosport, Waterlooville, Farnborough, Eastleigh, Winchester. Homes across the South East range from Victorian terraces in the older town centres to large detached houses on the edges, so the right extension type varies street by street.
Do I need planning permission in Hampshire?
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.
The planning position for a specific Hampshire address depends on its history and any designations, which is why we check it at the first visit.
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).
From first visit to completion
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 Hampshire home, measure up, talk through what you want and check the planning position.
Design and approvals
Once the layout is agreed, we deal with the council: planning permission or written confirmation that none is needed, plus building control.
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
Our team builds the extension, keeps you updated weekly and finishes with building control sign-off.
Common questions in Hampshire
Will my neighbours in Hampshire 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 you cover all of Hampshire?
Yes, across the whole of Hampshire. Site visits are free and there is no obligation.
Do I need building regulations approval in Hampshire?
Yes. Almost every extension needs it, whatever the planning route. We prepare the drawings and book the inspections.
What are the insulation standards for an extension?
In England, new walls in an extension should achieve a U-value of 0.18 W/m²K, roofs 0.15 and floors 0.18, with windows at 1.4 and rooflights at 2.2. Wales, Scotland and Northern Ireland set their own figures.
Full plans or building notice?
A full plans application gets the drawings checked before work starts, which we usually recommend for extensions. A building notice is quicker to submit but carries more risk if something needs changing on site.
Book a free site visit in Hampshire
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.