Company lists · Data refreshed September 2026

Top 25 Custom window builders based in the United Kingdom

Name: Custom window builders based in the United Kingdom
Creator: RevenueBase
License: https://creativecommons.org/licenses/by/4.0/

Compiled by the RevenueBase Data Team Data refreshed Sep 19, 2026 1,390 companies tracked

RevenueBase identified 1,390 custom window builders headquartered in the United Kingdom as of September 2026 and tracks 9,108 professional contacts across them, including 2,699 with verified work emails. London is the largest hub.

This list covers custom window builders headquartered in the United Kingdom, matched on what each company actually does as described in its own words. Ranked by team size, largest first. Every row shows the company's own description, its RevenueBase Smart Search rating, and when it was last checked. Data refreshed September 19, 2026.

Published by RevenueBase, a B2B data infrastructure company. This list was built with RevenueBase Smart Search, the natural-language company search RevenueBase customers use to build their own targeted lists and unlock verified emails and direct dials at the companies on them. How these lists are built and judged.

How to read this list HQ checked on every row RevenueBase Smart Search rating on every row Refreshed Sep 19, 2026 86% judged on-target in blind review

1,390Companies

9,108Contacts tracked

2,699Verified emails

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The 25 largest custom window builders based in the United Kingdom

Ranked by team size

Top 25 of 1,390 custom window builders based in the United Kingdom, ranked by team size, largest first. Data refreshed Sep 19, 2026. RevenueBase Smart Search rates how each company's information relates to custom window builders: strong evidence (its own description names it), partial (names part of it), indirect (matched on the rest of its profile rather than the description shown). Click a contact count to view that company's people.
#	Company	RevenueBase Smart Search	Headquarters	Employees	Contacts
1	First Home Improvements	Indirect evidence	Norwich, United KingdomHQ checked Sep 19, 2026	201-500	248 contacts →
	Indirect evidence “First Home Improvements traces its roots to the 1970's and prides itself on installing highly innovative A rated energy saving products unrivaled by many others within our…” Source: RevenueBase Database · checked Sep 19, 2026
2	Nordan UK LTD	Partial evidence	Livingston, United KingdomHQ checked Sep 19, 2026	51-200	154 contacts →
	Partial evidence “NorDan is one of Europe’s leading manufacturers of high performance windows, doors and smart accessories.” Source: RevenueBase Database · checked Sep 19, 2026
3	CR Smith	Indirect evidence	Dunfermline, United KingdomHQ checked Sep 19, 2026	201-500	150 contacts →
	Indirect evidence “With the vision of our Chairman, Gerard Eadie CBE, CR Smith has grown over the past 50 years to become Scotland’s leading home improvement company.” Source: RevenueBase Database · checked Sep 19, 2026
4	Press Glass UK	Indirect evidence	Swansea, United KingdomHQ checked Sep 19, 2026	1,001-5,000	132 contacts →
	Indirect evidence “PRESS GLASS WE ARE HERE TO MAKE A DIFFERENCE.” Source: RevenueBase Database · checked Sep 19, 2026
5	Nationwide Windows And Doors	Partial evidence	Rugby, United KingdomHQ checked Sep 19, 2026	501-1,000	126 contacts →
	Partial evidence “Manufacturers and Installers of PVCu Windows and Doors,Composite and Fire Doors and Conservatories to the Retail, Trade and Commercial Sector.” Source: RevenueBase Database · checked Sep 19, 2026
6	Emplas Window Systems	Partial evidence	Wellingborough, United KingdomHQ checked Sep 19, 2026	201-500	117 contacts →
	Partial evidence “Emplas is the window and door fabricator of choice, offering a complete range of premium-quality, high-security, energy-efficient windows and doors for the trade installer, new…” Source: RevenueBase Database · checked Sep 19, 2026
7	Aluk GB	Partial evidence	Chepstow, United KingdomHQ checked Sep 19, 2026	201-500	98 contacts →
	Partial evidence “For more than 40 years across the world, AluK has been at the forefront of the design of aluminium curtain walling, window and door systems, combining unique and innovative…” Source: RevenueBase Database · checked Sep 19, 2026
8	KAT UK Macclesfield	Partial evidence	Macclesfield, United KingdomHQ checked Sep 19, 2026	51-200	82 contacts →
	Partial evidence “KAT UK is a Macclesfield based manufacturer of specialist glazing products, including Aluminium and PVCu bifold doors, sliding patio doors, entrance doors, French doors, windows…” Source: RevenueBase Database · checked Sep 19, 2026
9	CSJ	Indirect evidence	Falkirk, United KingdomHQ checked Sep 19, 2026	51-200	81 contacts →
	Indirect evidence “CSJ are providers of bespoke solutions to complement any home.” Source: RevenueBase Database · checked Sep 19, 2026
10	SIDEY	Partial evidence	Perth, United KingdomHQ checked Sep 19, 2026	51-200	76 contacts →
	Partial evidence “Since our foundation in 1932, Sidey’s programme of sustainable and controlled growth has resulted in the company becoming one of the most successful and sustainable window and…” Source: RevenueBase Database · checked Sep 19, 2026
11	Schüco UK And Ireland	Partial evidence	Milton Keynes, United KingdomHQ checked Sep 19, 2026	51-200	71 contacts →
	Partial evidence “With over 30 years of experience, Schüco UK Ltd is a leading building envelope specialist supplying high-quality system solutions in aluminium and steel for windows, doors…” Source: RevenueBase Database · checked Sep 19, 2026
12	Unique Window Systems LTD	Partial evidence	Leicester, United KingdomHQ checked Sep 19, 2026	201-500	71 contacts →
	Partial evidence “An award-winning designer, fabricator and installer of UPVC and aluminium windows, doors and curtain walling, Unique Window Systems Ltd specialises in the supply of quality…” Source: RevenueBase Database · checked Sep 19, 2026
13	Crittall Windows LTD	Partial evidence	Witham, United KingdomHQ checked Sep 19, 2026	201-500	69 contacts →
	Partial evidence “Founded in the 1800's, CRITTALL WINDOWS Ltd was the pioneer of hot-rolled steel windows and was responsible for setting up the first steel window manufacturing plants in the…” Source: RevenueBase Database · checked Sep 19, 2026
14	Polyframe	Partial evidence	Lenwade, United KingdomHQ checked Sep 19, 2026	201-500	66 contacts →
	Partial evidence “Polyframe are a multi award-winning manufacturer of high quality windows, doors and conservatories.” Source: RevenueBase Database · checked Sep 19, 2026
15	VBH GB	Indirect evidence	Gillingham, United KingdomHQ checked Sep 19, 2026	51-200	62 contacts →
	Indirect evidence “VBH is the largest company in the hardware sector.” Source: RevenueBase Database · checked Sep 19, 2026
16	Glazerite UK Group LTD	Indirect evidence	Wellingborough, United KingdomHQ checked Sep 19, 2026	201-500	61 contacts →
	Indirect evidence “Glazerite UK Group is a leading trade fabricator offering installers access to one of the most comprehensive product ranges in the industry.” Source: RevenueBase Database · checked Sep 19, 2026
17	Senior Architectural Systems	Indirect evidence	Doncaster, United KingdomHQ checked Sep 19, 2026	51-200	60 contacts →
	Indirect evidence “Senior Architectural Systems (Senior) is one of the UK's leading manufacturers of aluminium fenestration solutions.” Source: RevenueBase Database · checked Sep 19, 2026
18	JPJ Installations LTD	Partial evidence	Braintree, United KingdomHQ checked Sep 19, 2026	51-200	57 contacts →
	Partial evidence “JPJ Installations Ltd are specialists in Aluminium Glazing Systems including Curtain Wall, Framing, Door and Window Systems.” Source: RevenueBase Database · checked Sep 19, 2026
19	Express Bi-Folding Doors	Indirect evidence	Leeds, United KingdomHQ checked Sep 19, 2026	201-500	56 contacts →
	Indirect evidence “Express Bi Folding Doors are the UK's leading manufacturer & installer of bespoke aluminium products.” Source: RevenueBase Database · checked Sep 19, 2026
20	Fleetwood Architectural Aluminium LTD	Partial evidence	Slough, United KingdomHQ checked Sep 19, 2026	51-200	56 contacts →
	Partial evidence “Fleetwood Architectural Aluminium (FAA) is one of the UK’s leading designers, manufacturers and installers of aluminium curtain walling, facades, windows and doors.” Source: RevenueBase Database · checked Sep 19, 2026
21	CWG Choices Limited	Partial evidence	Corby, United KingdomHQ checked Sep 19, 2026	201-500	50 contacts →
	Partial evidence “CWG Choices Ltd is a double glazing supplier of windows, doors, conservatories and garden studios/offices.” Source: RevenueBase Database · checked Sep 19, 2026
22	Modplan Limited	Indirect evidence	Gwent, United KingdomHQ checked Sep 19, 2026	51-200	47 contacts →
	Indirect evidence “Our business is to support your business Modplan is a trade-only fabricator.” Source: RevenueBase Database · checked Sep 19, 2026
23	Munster Joinery U.K	Partial evidence	Warwick, United KingdomHQ checked Sep 19, 2026	1,001-5,000	45 contacts →
	Partial evidence “For 50 years in business, Munster Joinery is now among Europe's largest manufacturers of energy-efficient windows and doors.” Source: RevenueBase Database · checked Sep 19, 2026
24	Vision Arch	Indirect evidence	Cambridge, United KingdomHQ checked Sep 19, 2026	11-50	44 contacts →
	Indirect evidence “Vision Arch has been designing and installing high-quality bespoke architectural facades, roof glazing, and glass atria for over 26 years now, mainly within the commercial sector.” Source: RevenueBase Database · checked Sep 19, 2026
25	Crystal Windows And Doors LTD	Strong evidence	Romford, United KingdomHQ checked Sep 19, 2026	201-500	43 contacts →
	Strong evidence “Crystal® was started in 1995 to offer a fair and honest service to customers wanting replacement windows and doors.” Source: RevenueBase Database · checked Sep 19, 2026

RevenueBase Smart Search

RevenueBase Smart Search assesses information from a company’s LinkedIn profile, information supplied directly by the company, its website, and other publicly available sources. It uses that information to rate how closely the company relates to this list’s category: custom window builders. Every row carries its rating and the description the rating was read from, so each one can be checked rather than taken on trust.

Strong evidence: The company's own public description of its business names custom window builders.
Partial evidence: Its own public description names part of custom window builders, so it works in or next to the category without describing itself that way.
Indirect evidence: The description shown does not name custom window builders. The match rests on the rest of the company's public profile rather than the one sentence quoted here, so this is the rating to check first.

RevenueBase Smart Search is how these lists are built: RevenueBase's data engine and AI assemble the companies that match a category defined in a user's own words, so a list can be about what companies actually do rather than about whichever industry code they were filed under.

Showing 25 of 1,390 custom window builders based in the United Kingdom

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Custom window builders based in the United Kingdom at a glance

As of Sep 19, 2026

29.6%Verified-email coverage

6.6Average contacts per company

11-50Median size (employees)

6.7%Largest-city concentration · London

Sep 19, 2026Page data refreshed

Companies by employee count

1-10

677

11-50

470

51-200

165

201-500

501-1,000

1,001-5,000

Email recency for this list is measured worldwide rather than for United Kingdom, so it is reported there. Company counts and contact totals on this page are exact for United Kingdom, over 1,390 companies.

How this list was built

Company categories are rarely black and white. RevenueBase reads each company's own description of its business to decide whether it belongs among custom window builders, so some rows will be adjacent to the category rather than pure plays. The description and RevenueBase Smart Search rating on every row are there so you can check each match yourself.

Source: The RevenueBase company graph: 60 million companies and 398.9 million professional contacts resolved from primary sources, queried with RevenueBase Smart Search, the natural-language company search available to every RevenueBase user.
What qualifies: Companies headquartered in the United Kingdom whose own description of what they do matches “custom window builders”. Matching reads each company's description, not its industry code or its name.
RevenueBase Smart Search: RevenueBase Smart Search is how this list is assembled and how each row is rated. RevenueBase's data engine and AI assess a company's LinkedIn profile, information supplied directly by the company, its website and other publicly available information, then relate it to a category defined in a user's own words. Each row is rated strong evidence (its own description names custom window builders), partial evidence (it names part of the category) or indirect evidence (the description shown names none of it and the match rests on the rest of the company's profile). The description supporting each rating is quoted on the row.
What we exclude: Companies whose own description does not clearly place them among custom window builders, and records with no verified work email. Companies headquartered outside United Kingdom are excluded even when they keep an office there.
Match quality: In blind human judging of this matching method, 86% of matched companies were on target. Expect roughly 1 in 7 rows to be adjacent to the category rather than a pure play. Every row shows the company's own description and its RevenueBase Smart Search rating so you can judge each match yourself. Read the full methodology: how the lists are built, how the judging worked, and what the figure means.
Ranking: Team size, largest first: companies are ordered by the number of professionals RevenueBase tracks at each one. Employee ranges shown are reported bands, for context.
Verification: Every listed company carries at least one verified work email, 2,699 across the full list. Contacts re-verify on a rolling cadence, and each contact's own verification date is shown inside RevenueBase.
Refresh: This page's figures were pulled from the company graph on September 19, 2026. Lists refresh periodically as the graph is re-checked.
Corrections: Wrong category, wrong headquarters, or a company that has closed? Use “Report an issue” on any row. Reports go to the RevenueBase Data Team and feed back into the company graph.

Custom window builders by metro

Custom window builders in London93

Frequently asked

What is RevenueBase Smart Search?

RevenueBase Smart Search is how RevenueBase decides which companies belong on this list and how strongly each one fits. Its data engine and AI assess a company's LinkedIn profile, information supplied directly by the company, its website and other publicly available information, then relate it to the category the list is about. Each row is rated strong evidence when the company's own description names custom window builders, partial evidence when it names part of the category, and indirect evidence when the description shown names none of it and the match rests on the rest of the company's profile.

How many custom window builders are there based in the United Kingdom?

RevenueBase identified 1,390 custom window builders headquartered in the United Kingdom as of September 2026, matched on each company's own description of what it does rather than its industry code.

What is the largest company on this list?

First Home Improvements, headquartered in Norwich, tops this list with the largest team on record.

Which city has the most custom window builders?

London leads with 93 headquartered companies, followed by Leicester (17) and Norwich (16).

How do I get contact information for these companies?

A free RevenueBase account lets you run this exact search and work the top results, verified emails and direct dials included. Upgrading unlocks all 2,699 verified decision-maker contacts tracked across these 1,390 companies.

How current is this list?

The list refreshes periodically as the company graph is re-checked. This page's figures were pulled on September 19, 2026.

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About this data

RevenueBase is a B2B data infrastructure company. Its company graph covers 60 million companies and 398.9 million professional contacts, with emails verified on a rolling cadence rather than scraped once and left to decay. These company lists are generated directly from that graph with RevenueBase Smart Search, the same natural-language company search every RevenueBase user has: describe a market in plain words, get the companies that match, and add verified emails and direct dials for the people at them. It is the same data that powers RevenueBase's B2B data products, and a free account includes 500 credits to start. How these lists are built and judged.