Company lists · Data refreshed September 2026

Top 25 Building systems integrators based in the United States

RevenueBase identified 4,300 building systems integrators headquartered in the United States as of September 2026 and tracks 110,520 professional contacts across them, including 48,677 with verified work emails. Houston is the largest hub.

This list covers building systems integrators headquartered in the United States, 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.

How to read this list HQ checked on every row RevenueBase Smart Search rating on every row Refreshed Sep 27, 2026 86% judged on-target in blind review
4,300Companies
110,520Contacts tracked
48,677Verified emails
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The 25 largest building systems integrators based in the United States

Ranked by team size
Top 25 of 4,300 building systems integrators based in the United States, ranked by team size, largest first. Data refreshed Sep 27, 2026. RevenueBase Smart Search rates how each company's information relates to building systems integrators: 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.
#CompanyRevenueBase Smart SearchHeadquartersEmployeesContacts
1Strong evidenceHoffman Estates, IL, United StatesHQ checked Sep 27, 202610001+5,707 contacts →

Strong evidence

“Convergint is a global systems integrator focused on delivering results for our customers through unparalleled service excellence.”

Source: RevenueBase Database · checked Sep 27, 2026
2Strong evidenceGarden Grove, CA, United StatesHQ checked Sep 27, 202610001+2,439 contacts →

Strong evidence

“As one of the nation's largest building systems experts, Southland Industries provides innovative, practical results for your engineering, construction, service, and energy needs.”

Source: RevenueBase Database · checked Sep 27, 2026
3Partial evidencePasadena, CA, United StatesHQ checked Sep 27, 20265,001-10,0002,415 contacts →

Partial evidence

“Since 1934, owners and builders have selected ACCO Engineered Systems to design, install, and maintain more than mechanical projects.”

Source: RevenueBase Database · checked Sep 27, 2026
4Indirect evidenceNorwalk, CT, United StatesHQ checked Sep 27, 202610001+1,383 contacts →

Indirect evidence

“A Fortune 500® company and a member of the S&P 500, EMCOR Group, Inc.(NYSE: EME) is a leader in mechanical and electrical construction, industrial and energy infrastructure, and…”

Source: RevenueBase Database · checked Sep 27, 2026
5Partial evidenceHouston, TX, United StatesHQ checked Sep 27, 202610001+1,330 contacts →

Partial evidence

“Comfort Systems USA | Quality People.”

Source: RevenueBase Database · checked Sep 27, 2026
6Strong evidenceAurora, OH, United StatesHQ checked Sep 27, 20261,001-5,0001,159 contacts →

Strong evidence

“As one of the world's largest independent systems integrators, RoviSys delivers comprehensive automation, digital transformation, manufacturing execution (MES), Industrial AI…”

Source: RevenueBase Database · checked Sep 27, 2026
7Strong evidenceKennesaw, GA, United StatesHQ checked Sep 27, 2026501-1,0001,115 contacts →

Strong evidence

“Automated Logic Corporation (ALC) provides innovative building automation and control systems.”

Source: RevenueBase Database · checked Sep 27, 2026
8Indirect evidenceAtlanta, GA, United StatesHQ checked Sep 27, 20261,001-5,0001,077 contacts →

Indirect evidence

“McKenney’s is the Southeast’s most trusted name in facility construction, operation and maintenance.”

Source: RevenueBase Database · checked Sep 27, 2026
9Indirect evidenceLouisville, KY, United StatesHQ checked Sep 27, 2026501-1,000936 contacts →

Indirect evidence

“CMTA is part of Legence, a Nasdaq Listed company.”

Source: RevenueBase Database · checked Sep 27, 2026
10Indirect evidenceJacksonville, FL, United StatesHQ checked Sep 27, 2026501-1,000899 contacts →

Indirect evidence

“Stellar, headquartered in Jacksonville, Florida, is a fully integrated firm focusing on design, engineering, construction, refrigeration, and mechanical and electrical services…”

Source: RevenueBase Database · checked Sep 27, 2026
11Indirect evidenceLewisville, TX, United StatesHQ checked Sep 27, 20261,001-5,000857 contacts →

Indirect evidence

“Prime Controls was established as a Main Automation Contractor to provide customers a sole source solution for Industrial Automation services and products.”

Source: RevenueBase Database · checked Sep 27, 2026
12Partial evidenceFond Du Lac, WI, United StatesHQ checked Sep 27, 20261,001-5,000849 contacts →

Partial evidence

“Ahern is a mechanical and fire protection contractor specializing in HVAC, Plumbing, Building Controls, Sprinkler, Extinguisher & Alarm and Fabrication for construction and…”

Source: RevenueBase Database · checked Sep 27, 2026
13Partial evidenceTampa, FL, United StatesHQ checked Sep 27, 20261,001-5,000745 contacts →

Partial evidence

“Limbach is a leading building solutions firm delivering mission critical infrastructure that supports life’s most important moments.”

Source: RevenueBase Database · checked Sep 27, 2026
14Partial evidenceSt. Louis, MO, United StatesHQ checked Sep 27, 20261,001-5,000744 contacts →

Partial evidence

“ArchKey, one of the largest privately held specialty trade installation and facilities services companies in the United States, is a leader in designing, building, and maintaining…”

Source: RevenueBase Database · checked Sep 27, 2026
15Partial evidenceEdison, NJ, United StatesHQ checked Sep 27, 20261,001-5,000669 contacts →

Partial evidence

“Albireo Energy is a leading independent building controls and energy services provider recognized by customers for creating intelligent, high-performance buildings.”

Source: RevenueBase Database · checked Sep 27, 2026
16Indirect evidenceAnkeny, IA, United StatesHQ checked Sep 27, 20261,001-5,000655 contacts →

Indirect evidence

“Established in 1963, Baker Group is Iowa’s premier full-service specialty contractor-serving commercial, industrial, institutional, and mission-critical markets across the country.”

Source: RevenueBase Database · checked Sep 27, 2026
17Indirect evidenceNorthbrook, IL, United StatesHQ checked Sep 27, 20261,001-5,000564 contacts →

Indirect evidence

“At F.E.”

Source: RevenueBase Database · checked Sep 27, 2026
18Strong evidenceAurora, OH, United StatesHQ checked Sep 27, 20261,001-5,000547 contacts →

Strong evidence

“As part of the RoviSys family of companies, we deliver vendor independent building automation, electrical power management, facility monitoring, and systems integration solutions…”

Source: RevenueBase Database · checked Sep 27, 2026
19Partial evidenceHigh Point, NC, United StatesHQ checked Sep 27, 20261,001-5,000545 contacts →

Partial evidence

“For generations, EAS Companies has been an innovative provider delivering complete solutions in mechanical, electrical, plumbing, building services, controls, and engineered…”

Source: RevenueBase Database · checked Sep 27, 2026
20Indirect evidenceIndianapolis, IN, United StatesHQ checked Sep 27, 20261,001-5,000539 contacts →

Indirect evidence

“DEEM, LLC is a mechanical and electrical company centrally located in Fishers, Indiana with satellite offices throughout the Midwest down to the southeastern United States.”

Source: RevenueBase Database · checked Sep 27, 2026
21Indirect evidenceCharlotte, NC, United StatesHQ checked Sep 27, 2026501-1,000470 contacts →

Indirect evidence

“Since 1996, MSS has made thousands of facilities more efficient, comfortable, secure and reliable for owners, operators and occupiers across the Carolinas and throughout North…”

Source: RevenueBase Database · checked Sep 27, 2026
22Partial evidenceEast Windsor, NJ, United StatesHQ checked Sep 27, 2026201-500455 contacts →

Partial evidence

“Thermo Systems is a full-service control systems integration partner, providing world-class automation solutions within the Energy, Life Sciences, and Mission Critical markets.”

Source: RevenueBase Database · checked Sep 27, 2026
23Indirect evidenceSan Diego, CA, United StatesHQ checked Sep 27, 2026201-500455 contacts →

Indirect evidence

“Our Mission: TIG will earn its place as a trusted partner to our clients, providing only the highest level of service, value and advanced technology to power their strategic…”

Source: RevenueBase Database · checked Sep 27, 2026
24Partial evidenceLittleton, CO, United StatesHQ checked Sep 27, 2026501-1,000453 contacts →

Partial evidence

“Since 1965, LONG has been in the business of building performance; making them automated, efficient, green, and safe.”

Source: RevenueBase Database · checked Sep 27, 2026
25Partial evidenceShelby Twp., MI, United StatesHQ checked Sep 27, 2026501-1,000447 contacts →

Partial evidence

“Fori Automation, LLC is a global leader in the design, build, and integration of custom material handling, assembly, testing, and welding systems.”

Source: RevenueBase Database · checked Sep 27, 2026

Showing 25 of 4,300 building systems integrators based in the United States

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Building systems integrators based in the United States at a glance

As of Sep 27, 2026
44.0%Verified-email coverage
25.7Average contacts per company
11-50Median size (employees)
1.9%Largest-city concentration · Houston
Sep 27, 2026Page data refreshed

Companies by employee count

1-10
1,527
11-50
1,758
51-200
746
201-500
151
501-1,000
54
1,001-5,000
40
5,001-10,000
6
10001+
10

Email recency for this list is measured worldwide rather than for United States, so it is reported there. Company counts and contact totals on this page are exact for United States, over 4,300 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 States 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 States 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, 48,677 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 States?

RevenueBase identified 4,300 building systems integrators headquartered in the United States 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?

Convergint, headquartered in Hoffman Estates, tops this list with the largest team on record.

Which city has the most building systems integrators?

Houston leads with 83 headquartered companies, followed by New York (72) and Dallas (42).

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 48,677 verified decision-maker contacts tracked across these 4,300 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.