Company lists · Data refreshed September 2026

Top 25 Building systems engineering firms based in the United States

Name: Building systems engineering firms based in the United States
Creator: RevenueBase
License: https://creativecommons.org/licenses/by/4.0/

Compiled by the RevenueBase Data Team Data refreshed Sep 16, 2026 3,172 companies tracked

RevenueBase identified 3,172 building systems engineering firms headquartered in the United States as of September 2026 and tracks 89,693 professional contacts across them, including 41,790 with verified work emails. New York is the largest hub.

This list covers building systems engineering firms 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 16, 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 16, 2026 86% judged on-target in blind review

3,172Companies

89,693Contacts tracked

41,790Verified emails

Explore this list → Free signup · no credit card · 500 free credits

The 25 largest building systems engineering firms based in the United States

Ranked by team size

Top 25 of 3,172 building systems engineering firms based in the United States, ranked by team size, largest first. Data refreshed Sep 16, 2026. RevenueBase Smart Search rates how each company's information relates to building systems engineering firms: 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	Southland Industries	Strong evidence	Garden Grove, CA, United StatesHQ checked Sep 16, 2026	10001+	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 16, 2026
2	IMEG	Partial evidence	Rock Island, IL, United StatesHQ checked Sep 16, 2026	1,001-5,000	1,985 contacts →
	Partial evidence “Leaders in Engineering and Innovation.” Source: RevenueBase Database · checked Sep 16, 2026
3	Bowman Consulting	Partial evidence	Reston, VA, United StatesHQ checked Sep 16, 2026	1,001-5,000	1,666 contacts →
	Partial evidence “Headquartered in Reston, Virginia, Bowman is a national engineering services firm delivering infrastructure solutions to customers who own, develop and maintain the built…” Source: RevenueBase Database · checked Sep 16, 2026
4	Emcor Group, INC	Indirect evidence	Norwalk, CT, United StatesHQ checked Sep 16, 2026	10001+	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 16, 2026
5	Mckenney's, INC	Indirect evidence	Atlanta, GA, United StatesHQ checked Sep 16, 2026	1,001-5,000	1,077 contacts →
	Indirect evidence “McKenney’s is the Southeast’s most trusted name in facility construction, operation and maintenance.” Source: RevenueBase Database · checked Sep 16, 2026
6	Henderson Engineers	Strong evidence	Lenexa, KS, United StatesHQ checked Sep 16, 2026	501-1,000	1,040 contacts →
	Strong evidence “Henderson Engineers is a national building systems design firm with a wide array of engineering services and a portfolio representing a full range of markets including business…” Source: RevenueBase Database · checked Sep 16, 2026
7	Affiliated Engineers, INC	Strong evidence	Madison, WI, United StatesHQ checked Sep 16, 2026	1,001-5,000	1,012 contacts →
	Strong evidence “Affiliated Engineers, Inc.(AEI) provides engineering leadership and whole-mission solutions for complex building, energy, and utility projects.” Source: RevenueBase Database · checked Sep 16, 2026
8	Simpson Gumpertz & Heger SGH	Partial evidence	Waltham, MA, United StatesHQ checked Sep 16, 2026	501-1,000	942 contacts →
	Partial evidence “Simpson Gumpertz & Heger (SGH) is a national engineering firm committed to delivering holistic advice for our clients’ most complex challenges.” Source: RevenueBase Database · checked Sep 16, 2026
9	Cmta, INC	Indirect evidence	Louisville, KY, United StatesHQ checked Sep 16, 2026	501-1,000	936 contacts →
	Indirect evidence “CMTA is part of Legence, a Nasdaq Listed company.” Source: RevenueBase Database · checked Sep 16, 2026
10	Stellar	Partial evidence	Jacksonville, FL, United StatesHQ checked Sep 16, 2026	501-1,000	899 contacts →
	Partial 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 16, 2026
11	Coffman Engineers	Indirect evidence	Seattle, WA, United StatesHQ checked Sep 16, 2026	501-1,000	859 contacts →
	Indirect evidence “The right team is more than an advantage.” Source: RevenueBase Database · checked Sep 16, 2026
12	Syska Hennessy Group	Indirect evidence	New York, United StatesHQ checked Sep 16, 2026	501-1,000	803 contacts →
	Indirect evidence “Consult Engineer Commission At Syska Hennessy Group, we create exceptional environments.” Source: RevenueBase Database · checked Sep 16, 2026
13	PAE	Strong evidence	Portland, OR, United StatesHQ checked Sep 16, 2026	201-500	744 contacts →
	Strong evidence “PAE provides mechanical and electrical engineering design, technology system design, energy modeling and analysis, and more.” Source: RevenueBase Database · checked Sep 16, 2026
14	ME Engineers	Partial evidence	Golden, CO, United StatesHQ checked Sep 16, 2026	201-500	696 contacts →
	Partial evidence “ME Engineers has earned a reputation as a global leader in the design of innovative MEPT systems that bring to life the world's most innovative sports and entertainment venues.” Source: RevenueBase Database · checked Sep 16, 2026
15	Ghafari Associates	Strong evidence	Dearborn, MI, United StatesHQ checked Sep 16, 2026	501-1,000	670 contacts →
	Strong evidence “An innovator since 1982, Ghafari embraces an integrated design approach to deliver solutions that synergize building operations, systems, and people.” Source: RevenueBase Database · checked Sep 16, 2026
16	Cadeploy	Partial evidence	Danville, CA, United StatesHQ checked Sep 16, 2026	501-1,000	638 contacts →
	Partial evidence “Constructing Certainty: Global Leaders in Precision BIM, Structural Steel Detailing, and Preconstruction Engineering.” Source: RevenueBase Database · checked Sep 16, 2026
17	Wunderlich-Malec Engineering, INC	Strong evidence	Eden Prairie, MN, United StatesHQ checked Sep 16, 2026	501-1,000	623 contacts →
	Strong evidence “Wunderlich-Malec Engineering is a nationally recognized, 100% employee-owned leader in advanced engineering and control system solutions.” Source: RevenueBase Database · checked Sep 16, 2026
18	Colonialwebb	Indirect evidence	Richmond, VA, United StatesHQ checked Sep 16, 2026	1,001-5,000	571 contacts →
	Indirect evidence “ColonialWebb is built on a simple belief: when people feel like they belong and have a purpose, they can achieve almost anything.” Source: RevenueBase Database · checked Sep 16, 2026
19	Enventure Engineering	Strong evidence	Chicago, IL, United StatesHQ checked Sep 16, 2026	501-1,000	569 contacts →
	Strong evidence “Enventure is a trusted provider of Building Engineering, Plant Design, and Compliance solutions with offices in the Chicago and delivery centres in Bangalore, Shivamogga, Hubli…” Source: RevenueBase Database · checked Sep 16, 2026
20	F.E. Moran Group Of Companies	Indirect evidence	Northbrook, IL, United StatesHQ checked Sep 16, 2026	1,001-5,000	564 contacts →
	Indirect evidence “At F.E.” Source: RevenueBase Database · checked Sep 16, 2026
21	Vanderweil Engineers	Partial evidence	Boston, MA, United StatesHQ checked Sep 16, 2026	201-500	545 contacts →
	Partial evidence “Vanderweil is a mechanical, electrical, plumbing, fire protection, technology, sustainability, commissioning, and power engineering firm dedicated to providing customized and…” Source: RevenueBase Database · checked Sep 16, 2026
22	RTM Engineering Consultants	Partial evidence	Schaumburg, IL, United StatesHQ checked Sep 16, 2026	201-500	516 contacts →
	Partial evidence “We are an engineering firm that goes beyond a typical consulting role.” Source: RevenueBase Database · checked Sep 16, 2026
23	T&m Associates	Partial evidence	Middletown, NJ, United StatesHQ checked Sep 16, 2026	201-500	516 contacts →
	Partial evidence “T&M Associates is a leading engineering and technical services firm focused on innovative solutions that advance our clients’ goals and sustain communities.” Source: RevenueBase Database · checked Sep 16, 2026
24	P1 Construction, LLC	Indirect evidence	Lenexa, KS, United StatesHQ checked Sep 16, 2026	1,001-5,000	497 contacts →
	Indirect evidence “P1 is built to bring trusted partnerships, facilities, and the communities we serve to life.” Source: RevenueBase Database · checked Sep 16, 2026
25	Therma	Indirect evidence	San Jose, CA, United StatesHQ checked Sep 16, 2026	1,001-5,000	482 contacts →
	Indirect evidence “Therma is part of Legence, a Blackstone portfolio company, specially created to be an Energy Transition Accelerator™.” Source: RevenueBase Database · checked Sep 16, 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: building systems engineering firms. 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 engineering firms.
Partial evidence: Its own public description names part of building systems engineering firms, so it works in or next to the category without describing itself that way.
Indirect evidence: The description shown does not name building systems engineering firms. 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 3,172 building systems engineering firms based in the United States

See the full list, filter by size, metro and specialty, and get verified emails and direct dials for all 41,790 reachable decision-makers.

Free signup · no credit card

View the full list →

Building systems engineering firms based in the United States at a glance

As of Sep 16, 2026

46.6%Verified-email coverage

28.3Average contacts per company

11-50Median size (employees)

2.9%Largest-city concentration · New York

Sep 16, 2026Page data refreshed

Companies by employee count

1-10

1,385

11-50

1,225

51-200

418

201-500

501-1,000

1,001-5,000

5,001-10,000

10001+

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 3,172 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 engineering firms, 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 engineering firms”. 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 engineering firms), 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 engineering firms, 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, 41,790 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 16, 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.

Building systems engineering firms by metro

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 engineering firms, 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 engineering firms are there based in the United States?

RevenueBase identified 3,172 building systems engineering firms 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?

Southland Industries, headquartered in Garden Grove, tops this list with the largest team on record.

Which city has the most building systems engineering firms?

New York leads with 91 headquartered companies, followed by Houston (62) and Austin (41).

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 41,790 verified decision-maker contacts tracked across these 3,172 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 16, 2026.

Ready to reach these companies? Verified emails and direct dials for all 3,172 building systems engineering firms based in the United States. Start with a free account, no credit card.

Download this list →

Related lists

Building systems engineering firms by geography

Browse the directory

Browse: Companies home · All United States lists · All Building systems engineering firms lists · New lists

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.