- Postcode district
- N3
- Survey
- Free for new and replacement doors
- Typical lead time
- Typically 4–6 weeks for aluminium and 2–4 weeks for uPVC after survey sign-off
- Guide price
- From £3,295 inc VAT
- Nearby
- Hendon, Mill Hill, Golders Green
- Building rules
- England
Are replacement sliding doors right for your Finchley home?
Most homeowners choosing replacement sliding doors want the same things: more light, a clear view and a door that is easy to live with.
If your Finchley home still has its original sliding patio door, look at the glass beads: if they are on the outside, a replacement will close off that weakness.
Selling a house in Finchley in the next few years? Keep the competent person scheme certificate or Building Control notice for the new door with your property paperwork.
- Multipoint locks, anti-lift devices and internally beaded glass close the security gaps that older patio doors commonly have, such as panels that can be lifted out.
- New rollers and a precision track make a heavy door glide with a light push, where an old door may need both hands and a firm shove to open.
- Certification through a competent person scheme installer, or notification to Building Control, is arranged as part of the job and gives you a record for when you sell.
Planning glass for the light in Finchley
Sun angles matter for big glazed doors. Around Finchley, midday sun reaches about 62° in summer and drops to about 15° in winter. That low winter sun is free heat through south-facing glass; high summer sun is easier to shade with a roof overhang, and solar-control glass helps where there is none.
Sliding door replacement prices in Finchley
Use these guide prices to budget. They include VAT, fitting and taking away an old door of a similar size. Taller doors, triple glazing and dual colour add to the figure — the online tool shows how much.
| Overall width | Typical panels | Guide price (fitted, inc VAT) |
|---|---|---|
| 3.0 m | 2 panels | £4,995–£6,095 |
| 3.6 m | 3 panels | £5,595–£6,895 |
| 4.8 m | 4 panels | £6,995–£8,495 |
See every size on the replacement sliding doors page or try the guide price tool.
How fitting works in Finchley
Here is the usual sequence in Finchley: guide price, free survey, written quote, then manufacture (typically 4–6 weeks for aluminium and 2–4 weeks for uPVC after survey sign-off). Fitting typically takes 1 day for a straight two-panel swap; 1–2 days for larger doors. Nearby, we also survey in Hendon, Mill Hill and Golders Green.
Rules for replacement sliding doors in England
In England, a replacement sliding door is a controlled fitting under the Building Regulations. In an existing home, a door with more than 60% glazing must reach a U-value of 1.4 W/m²K or better (or a Doorset Energy Rating of band C) under Approved Document L, and glass in doors must be safety glazing under Approved Document K. We arrange compliance through a competent person scheme installer or by notifying Building Control, and you receive the certificate.
Which options matter for replacement sliding doors?
- Slimline upgrade. Narrow interlocks for the maximum glass area the existing opening allows.
- New internal cill or board. A fresh window board or reveal lining to finish the inside neatly.
- Aluminium replacement. A thermally broken aluminium slider with slim frames and a durable powder-coat finish.
Questions about replacement sliding doors in Finchley
How soon can you survey in Finchley?
Surveys in the N3 district are booked at a time that suits you, and we offer survey dates when we reply to your enquiry. After you approve the written quote, manufacture is typically 4–6 weeks for aluminium and 2–4 weeks for uPVC after survey sign-off.
How long does it take to replace a sliding patio door?
Replacing a two-panel sliding patio door typically takes one day, from removing the old door to sealing and trimming the new one. Larger doors, three- or four-panel sets and doors needing extra making good typically take one to two days. Manufacture comes first, typically 4–6 weeks for aluminium or 2–4 weeks for uPVC after you sign off the surveyed specification.
Can I get a bigger door in the same opening?
You can usually get more glass in the same opening, because modern frames are slimmer, but the overall door size stays roughly the same as the old one. Making the door wider or taller means widening the opening, which is structural work with a steel beam, calculations and a Building Regulations application. Our new openings page covers that.
Is the survey free for a replacement door?
Yes, the survey for a replacement sliding door is free. We measure the opening, check its condition and the support above it, look at floor and outside levels, and talk through frame, glass and colour options. You then receive a written quote with the fixed price, and nothing is ordered until you confirm the surveyed specification in writing.

