Company lists · Data refreshed September 2026
Top 25 Building systems integrators based in the United Kingdom
RevenueBase identified 984 building systems integrators headquartered in the United Kingdom as of September 2026 and tracks 13,136 professional contacts across them, including 5,325 with verified work emails. London is the largest hub.
This list covers building systems integrators 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 27, 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.
The 25 largest building systems integrators based in the United Kingdom
Ranked by team size| # | Company | Contacts | |||
|---|---|---|---|---|---|
| 1 | 661 contacts → | ||||
Partial evidence “The FES Group is one of the largest independent technical services companies in the UK over 60 years of experience providing building services solutions to a wide range of…” Source: RevenueBase Database · checked Sep 27, 2026Thanks. The Data Team will review it. | |||||
| 2 | 505 contacts → | ||||
Partial evidence “Since 1931 we have been harnessing the natural elements to provide healthy, comfortable and safe working and living conditions in buildings.” Source: RevenueBase Database · checked Sep 27, 2026Thanks. The Data Team will review it. | |||||
| 3 | 493 contacts → | ||||
Strong evidence “Through our team of over 900 creative individuals, we've positioned ourselves as a respected force as a life safety systems integrator.” Source: RevenueBase Database · checked Sep 27, 2026Thanks. The Data Team will review it. | |||||
| 4 | 386 contacts → | ||||
Indirect evidence “Trinity’s mission statement is simple - to provide high quality design, installation, commissioning and long term after care of Fire Detection, Fire Suppression, Life Safety and…” Source: RevenueBase Database · checked Sep 27, 2026Thanks. The Data Team will review it. | |||||
| 5 | 312 contacts → | ||||
Indirect evidence “Space Engineering Services is the UK’s leading provider of refrigeration, heating, ventilation and air conditioning services.” Source: RevenueBase Database · checked Sep 27, 2026Thanks. The Data Team will review it. | |||||
| 6 | 270 contacts → | ||||
Partial evidence “Gratte Brothers Group is a leading independent provider of comprehensive building services, renowned for exceptional quality.” Source: RevenueBase Database · checked Sep 27, 2026Thanks. The Data Team will review it. | |||||
| 7 | 234 contacts → | ||||
Indirect evidence “For organisations facing the compounding threats of ageing assets, a retiring workforce, and evolving cyber attacks, the status quo is no longer an option.” Source: RevenueBase Database · checked Sep 27, 2026Thanks. The Data Team will review it. | |||||
| 8 | 218 contacts → | ||||
Strong evidence “BMSI is the UK’s largest & leading Independent systems integrator of Building Energy Management Systems (BEMS).” Source: RevenueBase Database · checked Sep 27, 2026Thanks. The Data Team will review it. | |||||
| 9 | 205 contacts → | ||||
Strong evidence “Part of the SCCI Group, SCCI Alphatrack designs, installs, and maintains connected building systems across social housing, commercial property, new builds, and public sector…” Source: RevenueBase Database · checked Sep 27, 2026Thanks. The Data Team will review it. | |||||
| 10 | 175 contacts → | ||||
Strong evidence “ABEC is one of the leading independent Building Management System (BMS) and Electrical Power Monitoring System (EPMS) specialists.” Source: RevenueBase Database · checked Sep 27, 2026Thanks. The Data Team will review it. | |||||
| 11 | 164 contacts → | ||||
Partial evidence “With 45+ years in business, Dowds expertise spans the full lifecycle of complex build environments – from initial design and systems integration to final handover and beyond.” Source: RevenueBase Database · checked Sep 27, 2026Thanks. The Data Team will review it. | |||||
| 12 | 156 contacts → | ||||
Partial evidence “Swegon is a market leading supplier of energy efficient indoor climate, cooling and life safety systems.” Source: RevenueBase Database · checked Sep 27, 2026Thanks. The Data Team will review it. | |||||
| 13 | 139 contacts → | ||||
Indirect evidence “Shaping the future, together.” Source: RevenueBase Database · checked Sep 27, 2026Thanks. The Data Team will review it. | |||||
| 14 | 138 contacts → | ||||
Partial evidence “MCS Ltd are specialist building services engineers covering all aspects of commercial and industrial building services and infrastructure engineering across varying market sectors.” Source: RevenueBase Database · checked Sep 27, 2026Thanks. The Data Team will review it. | |||||
| 15 | 132 contacts → | ||||
Partial evidence “Smith & Byford is a family-owned and operated building services company.” Source: RevenueBase Database · checked Sep 27, 2026Thanks. The Data Team will review it. | |||||
| 16 | 119 contacts → | ||||
Strong evidence “Cinos is an industry-leading, agile, and innovative systems integrator.” Source: RevenueBase Database · checked Sep 27, 2026Thanks. The Data Team will review it. | |||||
| 17 | 117 contacts → | ||||
Strong evidence “European Electronique is a leading UK systems Integrator, specialising in the delivery of secure technology platforms including Hybrid IT, Cyber Security and Networking…” Source: RevenueBase Database · checked Sep 27, 2026Thanks. The Data Team will review it. | |||||
| 18 | 114 contacts → | ||||
Indirect evidence “Neil Fisher started Airco in 1991.” Source: RevenueBase Database · checked Sep 27, 2026Thanks. The Data Team will review it. | |||||
| 19 | 113 contacts → | ||||
Strong evidence “Trend is one of the world's leading Building Energy Management Systems manufacturers, with a worldwide distribution and support network covering over 50 countries.” Source: RevenueBase Database · checked Sep 27, 2026Thanks. The Data Team will review it. | |||||
| 20 | 102 contacts → | ||||
Indirect evidence “We are EFT Group.” Source: RevenueBase Database · checked Sep 27, 2026Thanks. The Data Team will review it. | |||||
| 21 | 101 contacts → | ||||
Partial evidence “MSE are a midlands based building services company and have over 30 years experience in the commercial and industrial environment working with a broad range of clients.” Source: RevenueBase Database · checked Sep 27, 2026Thanks. The Data Team will review it. | |||||
| 22 | 94 contacts → | ||||
Indirect evidence “Better protect your people, places and spaces.” Source: RevenueBase Database · checked Sep 27, 2026Thanks. The Data Team will review it. | |||||
| 23 | 93 contacts → | ||||
Strong evidence “As a System Integrator for over 35 years, Adsyst (Automation) Ltd has been providing complex Control Systems for Process Control, Automation and Telemetry to customers worldwide.” Source: RevenueBase Database · checked Sep 27, 2026Thanks. The Data Team will review it. | |||||
| 24 | 83 contacts → | ||||
Indirect evidence “Connecting people, places, and possibilities through transformative workplace technology.” Source: RevenueBase Database · checked Sep 27, 2026Thanks. The Data Team will review it. | |||||
| 25 | 81 contacts → | ||||
Partial evidence “Grant Walker Engineering specialise in the complete installation of Electrical and Mechanical systems across all work sectors including quality office developments, commercial and…” Source: RevenueBase Database · checked Sep 27, 2026Thanks. The Data Team will review it. | |||||
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: building systems integrators. 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 building systems integrators.
- Partial evidence
- Its own public description names part of building systems integrators, so it works in or next to the category without describing itself that way.
- Indirect evidence
- The description shown does not name building systems integrators. 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 984 building systems integrators based in the United Kingdom
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Building systems integrators based in the United Kingdom at a glance
As of Sep 27, 2026Companies by employee count
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 984 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 building systems integrators, 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 “building systems integrators”. 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 building systems integrators), 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 building systems integrators, 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, 5,325 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 27, 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.
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 building systems integrators, 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 building systems integrators are there based in the United Kingdom?
RevenueBase identified 984 building systems integrators 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?
FES Group, headquartered in Stirling, tops this list with the largest team on record.
Which city has the most building systems integrators?
London leads with 145 headquartered companies, followed by Bristol (15) and Sheffield (14).
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 5,325 verified decision-maker contacts tracked across these 984 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 27, 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.
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