Building regulations for extensions in Friern Barnet
We prepare building regulations for extensions for homes in Friern Barnet, as a stand-alone service or as the first stage of a design and build project.
- Guide price in Friern BarnetFrom £1,150 inc VAT
- Approval routeFull plans or building notice
- Timescale2–5 weeks for drawings
- Postcode districtsN2, N3, N10, N11, N12
What is included
- 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
- Structural calculations for beams, lintels and foundations
- Inspection bookings throughout the build
- Building regulations drawings and written specification
Building regulations approval and planning permission are separate. A design can have planning consent and still need changes to meet the regulations, which is why we draw for both together.
Covering Friern Barnet
Postcode districts we cover around Friern Barnet include N2, N3, N10, N11, N12, N20. Nearby, we also take on projects in Muswell Hill (2 miles), Finchley (2 miles), Wood Green (2 miles), Palmers Green (2 miles).
Just over the Hertfordshire border, Potters Bar is about 6 miles away. London's housing is dominated by Victorian and Edwardian terraces, many with a rear outrigger and a side return, and 1930s semis in the outer boroughs. Conservation areas are common, so the planning check comes first.
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.
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).
Design and approval fees for Friern Barnet
Guide fees for Friern Barnet including VAT, using our London factor of ×1.3. Council and building control charges are not included.
| 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.
Try the guide-price tool to see a range for your own size and finish.
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
A designer visits, takes measurements and photos, and discusses layouts, budget and timing with you.
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
You receive a written, itemised price and programme. Nothing starts until you are happy with it.
Build and sign-off
Work is carried out to the agreed programme, inspected by building control and signed off at the end.
Questions answered
Can I see a price before committing to anything?
Yes. The guide prices on this page are adjusted for Friern Barnet, and the guide-price tool gives a range for your own size. After the survey you get a written price before anything is agreed.
Do I need building regulations approval in Friern Barnet?
Yes. Almost every extension needs it, whatever the planning route. We prepare the drawings and book the inspections.
Who do I contract with in Friern Barnet?
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.
Who are building control?
Either your local council’s building control team or a registered building control approver. Both inspect the work and issue the completion certificate.
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.
Book a free site visit in Friern 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.