Conservatory replacement extensions in Finchley: design, approvals and build
We design and build conservatory replacements for houses in Finchley, with a written price once the survey and design are done and one point of contact throughout.
- Guide price in FinchleyFrom £26,000 inc VAT
- PlanningOften permitted development (3–4 m), or prior approval up to 6–8 m
- Build time8–14 weeks on site
- Postcode districtsN2, N3, N12, NW4, NW7
Do I need planning permission in Finchley?
In England a single-storey rear extension can usually go up to 3 m beyond the original rear wall of a semi-detached or terraced house, or 4 m on a detached house, without a planning application, provided it is no more than 4 m high, keeps eaves to 3 m within 2 m of a boundary and, with other buildings, covers no more than half the land around the original house. The larger home extension prior approval scheme raises those depths to 6 m and 8 m, with neighbours notified and a 42-day decision.
Before any drawing is finalised we check whether the house is listed, in a conservation area or subject to an Article 4 direction.
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.
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).
Conservatory replacement prices in Finchley
Prices below are for Finchley, using the London factor of ×1.3. They are guide ranges including VAT for the build only, not a quote.
Typical rates in Finchley: £2,400 to £4,550 per m² including VAT, depending on specification.
| Size | Essential | Standard | Premium |
|---|---|---|---|
| 3 m × 3.3 m 10 m² | £26,000 – £31,000 | £27,500 – £36,000 | £35,500 – £45,500 |
| 3.5 m × 4 m 14 m² | £33,500 – £40,500 | £39,000 – £50,500 | £50,000 – £64,000 |
| 4 m × 5 m 20 m² | £48,000 – £57,500 | £55,500 – £71,500 | £71,500 – £91,000 |
Includes removal of the old conservatory. Reusing existing foundations is only possible after investigation.
For a figure based on your own dimensions, use our guide-price tool.
Covering Finchley
We cover Finchley and the postcode districts N2, N3, N12, NW4, NW7, NW11. The same team covers Golders Green (2 miles), Friern Barnet (2 miles), Muswell Hill (2 miles), Cricklewood (3 miles), all within easy reach.
Borehamwood, in Hertfordshire, is roughly 5 miles from Finchley and also on our list. Across London, terraced houses with narrow side returns and tight access are the norm, which shapes everything from party wall notices to how materials reach the back garden.
What we take care of
- Opening widened into the house if wanted
- New or upgraded foundations
- Removal and disposal of the old conservatory
- Trial holes to check the existing foundations
- Glazing and doors to suit the new room
A replacement is a chance to rethink the shape. Many conservatories are oddly proportioned; for a similar cost the new room can often be squarer, wider or better connected to the kitchen.
What happens next
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
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.
Your questions about a conservatory replacement in Finchley
Can I see a price before committing to anything?
Yes. The guide prices on this page are adjusted for Finchley, 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 Finchley?
Yes. Almost every extension needs it, whatever the planning route. We prepare the drawings and book the inspections.
How long does a conservatory replacement take to build in Finchley?
On site, typically 8 to 14 weeks once approvals are in place. Before that, allow 4–12 weeks design and approvals.
Can I keep the existing base?
Sometimes, but conservatory bases are often too shallow for solid walls. Trial holes tell us before we confirm the price.
Is it worth replacing a conservatory with an extension?
If the conservatory is unusable for much of the year, usually yes. A solid extension gives a heated room that counts as proper living space. Our guide range is about £2,400 to £4,550 per m² including VAT, including removal.
Book a free site visit in Finchley
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.