Building regulations for extensions across East Barnet
For East Barnet homeowners we handle building regulations for extensions, with fees agreed in writing before any work starts.
- Guide price in East BarnetFrom £1,150 inc VAT
- Approval routeFull plans or building notice
- Timescale2–5 weeks for drawings
- Postcode districtsEN4, EN5, N14, N20
What it costs in East Barnet
Fees below are our East Barnet guide (×1.3, the London factor), including VAT. Council and building control fees are extra.
| Option | What it covers | Guide price |
|---|---|---|
| Essential | Building regulations drawings for a simple single-storey extension | £1,150 – £2,350 |
| Standard | Drawings plus structural calculations | £1,650 – £3,400 |
| Premium | Complex or two-storey pack with energy calculations | £2,850 – £4,950 |
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.
Want a range for your exact size? The guide-price tool takes about a minute.
Covering East Barnet
We cover East Barnet and the postcode districts EN4, EN5, N14, N20. The same team covers Barnet (2 miles), Friern Barnet (2 miles), Palmers Green (3 miles), Enfield (3 miles), all within easy reach.
For homes towards Hertfordshire, Potters Bar is around 3 miles away. In London, space is at a premium and gardens are often short, so side returns, wraparounds and carefully planned rear extensions tend to make the most of every metre.
Will the council need to approve it?
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.
Before any drawing is finalised we check whether the house is listed, in a conservation area or subject to an Article 4 direction.
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 is included
- Structural calculations for beams, lintels and foundations
- Building regulations drawings and written specification
- Energy and glazing checks, including whole-house calculations if needed
- Submission to the council or a registered building control approver
- Completion certificate on sign-off
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
First, a site visit: we look at the house, garden, access and drains and listen to what you need.
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
We build it with one project manager, book the building control inspections and hand over the completion certificate.
Common questions in East Barnet
How long does this take for a East Barnet home?
2–5 weeks for drawings, depending on the council and the complexity of the project.
Do you cover all of East Barnet?
Yes. We cover East Barnet and the surrounding parts of Greater London. Site visits are free and there is no obligation.
Will my neighbours in East Barnet 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.
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 East Barnet
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.