6 Best Window Installers in North London for 2026

North London's housing stock makes window work more varied than almost anywhere else in the capital. You've got Victorian and Edwardian terraces in Crouch End, Stoke Newington and Tufnell Park with original timber sashes, 1930s semis across Barnet, Southgate and Finchley with steel-framed or early casement windows, and post-war estates in Enfield and Edmonton where uPVC replacements are the norm. Many streets sit inside conservation areas, such as Highgate, Hampstead Garden Suburb and parts of Islington, where planning rules can limit what you're allowed to fit on the front elevation. Listed buildings add another layer again.

The businesses on this page are drawn from third-party business listings and ranked by public review rating and review count, with a small lift for those that show a working website and phone. We read each business's homepage to confirm window installation is what they primarily offer, which keeps unrelated trades off the page. Permanently closed listings are removed automatically. Where you see a Trust Verified badge, that business has additionally passed our full verification covering trade qualifications and accreditations, public liability insurance, trading history, customer review history and registered company information. Our How We Verify page has the full list. For anyone without that badge, we haven't independently verified those things, so you'll want to check them yourself before you book.

Get at least two or three written quotes, and make sure each one spells out the glazing specification, frame material, colour, handle and hinge type, and whether removal of old windows is included. Ask whether the installer is registered with FENSA or CERTASS, because that's how replacement windows are signed off under Building Regulations, and you should receive a certificate once the job is done. Ask for proof of public liability insurance, and ask what the guarantee covers and who honours it if the company folds. In a conservation area, check who's responsible for any planning permission. Don't pay a large deposit upfront; a modest one tied to ordering the units is reasonable, with the balance due on completion.

How We Select & Rate The Best Window Installers in North London

Our ranking is driven by public review rating and review count drawn from third-party business listings, with a small lift for businesses that have a working website and phone. We read each business's homepage to confirm window installation is what they primarily offer, and permanently closed listings are removed automatically. Businesses marked Trust Verified have additionally passed our full verification covering trade qualifications and accreditations, public liability insurance, trading history, customer review history and registered company information. Our How We Verify page has the full list. Other businesses on this page have not been independently verified by us, and inclusion is not an endorsement. Always do your own checks before hiring.

Recommended and Featured listings are paid placements, so a business's fee affects whether and where it appears. Every other listing is ranked on rating and review count from third-party business listings. How we rank & verify →

Quick Comparison: Window Installers in North London

#	Business	Rating	Reviews	Phone
1	Wembley Windows SC Ltd	⭐ 4.4	118	020 8208 4100	View →
2	Ask Windows Limited	⭐ 4.7	62	020 8959 8979	View →
3	London Sash Windows & Doors Ltd	⭐ 4.9	41	0208 150 7153	View →
4	Woodway Windows	⭐ 4.9	38	07543 840537	View →
5	Sashed Ltd	⭐ 4.8	32	0800 195 2939	View →
6	Repair A Sash Limited	⭐ 4.8	5	07511 890440	View →

Our Top Picks

Wembley Windows SC Ltd

Not Verified

★★★★☆ 4.4 (118 reviews)

North London 020 8208 4100

Window installation across London, with Wembley Windows SC Ltd covering domestic and commercial properties from its NW2 base. The company holds a 4.4-star rating across 118 Google reviews, suggesting a consistent record with local customers. Supply and fitting of replacement windows forms the core of its work.

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Ask Windows Limited

Not Verified

★★★★★ 4.7 (62 reviews)

North London 020 8959 8979

Ask Windows Limited is a window installation company serving London from its NW7 base. The firm focuses on residential and commercial glazing, covering supply and fitting across the capital. With a straightforward name that reflects its trade, it offers a clear point of contact for homeowners and businesses looking to replace or upgrade windows.

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London Sash Windows & Doors Ltd

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★★★★★ 4.9 (41 reviews)

North London 0208 150 7153

Sash window restoration and installation is the core focus for London Sash Windows & Doors Ltd, a specialist working across London. The company handles both period property repairs and new sash installations, making it a practical option for homeowners dealing with draughty or failing timber windows. Their N19 postcode places them well for north London enquiries.

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Woodway Windows

Not Verified

★★★★★ 4.9 (38 reviews)

North London 07543 840537

Window installation across London, with a focus on residential properties in and around the N11 area. Woodway Windows carries a 4.9 Google rating from 38 reviews, suggesting consistent workmanship and reliable customer communication. The company handles supply and fitting, covering the range of frame materials and glazing options typical of a full-service window installer.

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Sashed Ltd

Not Verified

★★★★★ 4.8 (32 reviews)

North London 0800 195 2939

Sashed Ltd is a window installation company operating in London, specialising in sash windows. Working primarily across NW10 and the surrounding areas, the company focuses on the repair, restoration, and replacement of traditional sash window styles. Their work suits period properties where retaining the original character of a home matters as much as the practical result.

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Repair A Sash Limited

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★★★★★ 4.8 (5 reviews)

North London 07511 890440

Repair A Sash Limited focuses exclusively on sash windows, serving homeowners across London from its NW10 base. The narrow specialism means the company handles the full range of sash-related work, from draught-proofing and cord replacement to full restoration and new timber installations, without branching into unrelated glazing trades.

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Transparency notice: Recommended and Featured listings are paid placements, so a business's fee affects whether and where it appears. All other listings are ranked by a combined score drawn from ratings and review counts published on third-party business listings, plus basic completeness signals such as a working website and phone. A Trust Verified badge means we have independently checked that business's documents; businesses without it have not been independently verified by us. How we verify →

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Frequently Asked Questions

How much does a window installer cost in North London?

For uPVC double glazing, expect roughly £350 to £700 per standard casement window fitted, so a typical three-bed semi in Barnet or Enfield usually lands between £5,000 and £10,000 for the whole house. Aluminium frames cost more, often £800 to £1,500 per window. Timber sash windows are the priciest, commonly £1,200 to £2,500 each for new draught-proofed units, though restoring existing sashes can come in lower. Price varies with frame material, glazing spec (A-rated, triple, acoustic), window size, and whether scaffolding or tricky access in a terrace is needed. Getting two or three quotes is normal and worth doing.

Do I need planning permission to replace my windows in North London?

Usually not for a like-for-like replacement on a standard house, as it's generally treated as permitted development. The exceptions matter in North London, though. If you live in a conservation area, such as parts of Highgate, Crouch End, Muswell Hill or Hampstead Garden Suburb, an Article 4 Direction may remove those rights, particularly on front elevations. Listed buildings need listed building consent. Flats and maisonettes often don't have permitted development rights at all. Check with your local council's planning department before you order anything, and ask your installer who's taking responsibility for that check.

Can I keep my original sash windows rather than replacing them?

Often, yes. Many Victorian and Edwardian terraces across Stoke Newington, Tufnell Park and Islington have sashes that can be repaired, draught-proofed and re-corded rather than ripped out. Restoration typically costs £300 to £800 per window depending on condition, and it can be cheaper than replacement while keeping the character of the house. Secondary glazing is another option if you want better noise and heat performance without changing the front elevation, which is handy near busy roads like the A10 or North Circular.

How long does a window installation take?

Most installers fit a full set of windows in a typical house in one to three days, with roughly four to eight windows done per day by a two-person team. Lead times are the bigger wait. Made-to-measure uPVC units normally take three to six weeks from survey to delivery, while bespoke timber or aluminium can take eight to twelve weeks. Ask for a clear survey date, an order date and an installation window in writing, so you know when to expect disruption.

What guarantees and paperwork should I get after the work?

You should receive a FENSA or CERTASS certificate, or confirmation of Building Control sign-off, for replacement windows. You'll need it when you sell the property, so keep it safe. You should also get a written guarantee covering the frames, the glazed units (sealed unit failure and misting are the usual issues) and the workmanship, with the term stated in years. Ask whether the guarantee is insurance-backed, because that protects you if the installer stops trading.

How do I choose between window installers?

Start with the paperwork. Ask each company whether they hold relevant trade accreditation such as FENSA or CERTASS, and ask to see their public liability insurance certificate. Check how long they've been trading and look at their online reviews for patterns, particularly around after-sales service and how they handled problems. Ask for addresses of recent local jobs you can look at, or for references from customers in your area. Compare quotes line by line rather than on headline price, and be wary of anyone pushing a same-day discount or asking for most of the money upfront. Businesses without a Trust Verified badge haven't been independently verified by us, so these checks are down to you.

6 Best Window Installers in North London for 2026

Quick Comparison: Window Installers in North London

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