Company lists · Data refreshed September 2026
Top 25 Retrofit consultants based in the United States
RevenueBase identified 4,306 retrofit consultants headquartered in the United States as of September 2026 and tracks 79,228 professional contacts across them, including 35,540 with verified work emails. New York is the largest hub.
This list covers retrofit consultants 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 29, 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 retrofit consultants based in the United States
Ranked by team size| # | Company | Contacts | |||
|---|---|---|---|---|---|
| 1 | 4,156 contacts → | ||||
Indirect evidence “Sargent & Lundy is one of the world’s longest-standing full-service architect engineering firms.” Source: RevenueBase Database · checked Sep 29, 2026Thanks. The Data Team will review it. | |||||
| 2 | 2,177 contacts → | ||||
Indirect evidence “Langan's client-focused, highly entrepreneurial culture cultivates an environment of opportunities in which career growth and teamwork flourish.” Source: RevenueBase Database · checked Sep 29, 2026Thanks. The Data Team will review it. | |||||
| 3 | 1,985 contacts → | ||||
Indirect evidence “Leaders in Engineering and Innovation.” Source: RevenueBase Database · checked Sep 29, 2026Thanks. The Data Team will review it. | |||||
| 4 | 1,290 contacts → | ||||
Indirect evidence “Atwell is a full-service consulting, engineering and construction services firm that delivers a broad range of creative solutions to clients in the real estate and land…” Source: RevenueBase Database · checked Sep 29, 2026Thanks. The Data Team will review it. | |||||
| 5 | 1,145 contacts → | ||||
Indirect evidence “OLA Sustainability, LLC OLA Sustainability is a consulting firm that focuses on integrating sustainable practices into commercial and multifamily design projects.” Source: RevenueBase Database · checked Sep 29, 2026Thanks. The Data Team will review it. | |||||
| 6 | 1,012 contacts → | ||||
Indirect evidence “Affiliated Engineers, Inc.(AEI) provides engineering leadership and whole-mission solutions for complex building, energy, and utility projects.” Source: RevenueBase Database · checked Sep 29, 2026Thanks. The Data Team will review it. | |||||
| 7 | 942 contacts → | ||||
Indirect 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 29, 2026Thanks. The Data Team will review it. | |||||
| 8 | 822 contacts → | ||||
Indirect evidence “Introba is one of the world’s largest building engineering and consulting firms with more than employees in offices across the United States, Canada, the United Kingdom, Serbia…” Source: RevenueBase Database · checked Sep 29, 2026Thanks. The Data Team will review it. | |||||
| 9 | 803 contacts → | ||||
Indirect evidence “Consult Engineer Commission At Syska Hennessy Group, we create exceptional environments.” Source: RevenueBase Database · checked Sep 29, 2026Thanks. The Data Team will review it. | |||||
| 10 | 744 contacts → | ||||
Indirect evidence “PAE provides mechanical and electrical engineering design, technology system design, energy modeling and analysis, and more.” Source: RevenueBase Database · checked Sep 29, 2026Thanks. The Data Team will review it. | |||||
| 11 | 545 contacts → | ||||
Indirect 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 29, 2026Thanks. The Data Team will review it. | |||||
| 12 | 518 contacts → | ||||
Indirect evidence “Established in 1996, NOVA was originally founded to provide Environmental Consulting, Geotechnical Engineering, and Construction Materials Testing and Inspection services to the…” Source: RevenueBase Database · checked Sep 29, 2026Thanks. The Data Team will review it. | |||||
| 13 | 516 contacts → | ||||
Indirect evidence “We are an engineering firm that goes beyond a typical consulting role.” Source: RevenueBase Database · checked Sep 29, 2026Thanks. The Data Team will review it. | |||||
| 14 | 512 contacts → | ||||
Indirect evidence “Founded in New York City in 1969, DeSimone provides structural engineering, façade and building envelope consulting, vertical transportation consulting, forensics, structural…” Source: RevenueBase Database · checked Sep 29, 2026Thanks. The Data Team will review it. | |||||
| 15 | 467 contacts → | ||||
Indirect evidence “MBP is a multi-disciplined consulting firm that provides a broad range of professional services designed to mitigate risk and optimize value within the built environment.” Source: RevenueBase Database · checked Sep 29, 2026Thanks. The Data Team will review it. | |||||
| 16 | 465 contacts → | ||||
Indirect evidence “Jaros, Baum & Bolles, Inc.(JB & B) is a leading consulting engineering firm specializing in mechanical, electrical, plumbing, and fire protection (MEP/FP) systems for complex…” Source: RevenueBase Database · checked Sep 29, 2026Thanks. The Data Team will review it. | |||||
| 17 | 450 contacts → | ||||
Indirect evidence “SitelogIQ provides design, engineering, and construction management services that help organizations nationwide modernize their facilities and infrastructure.” Source: RevenueBase Database · checked Sep 29, 2026Thanks. The Data Team will review it. | |||||
| 18 | 441 contacts → | ||||
Partial evidence “Lerch Bates is the global multidisciplinary technical consultancy saving time and money for those designing, modernizing, investigating, or managing buildings.” Source: RevenueBase Database · checked Sep 29, 2026Thanks. The Data Team will review it. | |||||
| 19 | 404 contacts → | ||||
Indirect evidence “DCI Engineers has been providing client-focused structural and civil engineering services for over three decades.” Source: RevenueBase Database · checked Sep 29, 2026Thanks. The Data Team will review it. | |||||
| 20 | 399 contacts → | ||||
Indirect evidence “Founded in 1983, RMF Engineering provides planning, design, engineering, commissioning and facility assessment services globally to clients in the healthcare, higher education…” Source: RevenueBase Database · checked Sep 29, 2026Thanks. The Data Team will review it. | |||||
| 21 | 386 contacts → | ||||
Indirect evidence “Glumac, a Tetra Tech Company, is a global leader in building engineering, committed to delivering a low carbon future for all.” Source: RevenueBase Database · checked Sep 29, 2026Thanks. The Data Team will review it. | |||||
| 22 | 375 contacts → | ||||
Indirect evidence “P2S has brought forward-thinking, sustainable engineering solutions to California, the Pacific Northwest, and beyond, for over 30 years.” Source: RevenueBase Database · checked Sep 29, 2026Thanks. The Data Team will review it. | |||||
| 23 | 365 contacts → | ||||
Indirect evidence “Manhard Consulting has joined Atwell, a national consulting, engineering, and construction services firm with 2,100 technical professionals across the country.” Source: RevenueBase Database · checked Sep 29, 2026Thanks. The Data Team will review it. | |||||
| 24 | 363 contacts → | ||||
Indirect evidence “We help clients design and operate facilities that remain resilient, reliable, and ready for what's next.” Source: RevenueBase Database · checked Sep 29, 2026Thanks. The Data Team will review it. | |||||
| 25 | 355 contacts → | ||||
Indirect evidence “Wendel is an Architecture, Engineering, Energy Efficiency, and Construction Management Firm that delivers customized solutions and turnkey projects in innovative ways.” Source: RevenueBase Database · checked Sep 29, 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: retrofit consultants. 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 retrofit consultants.
- Partial evidence
- Its own public description names part of retrofit consultants, so it works in or next to the category without describing itself that way.
- Indirect evidence
- The description shown does not name retrofit consultants. 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 4,306 retrofit consultants based in the United States
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Retrofit consultants based in the United States at a glance
As of Sep 29, 2026Companies by employee count
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 4,306 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 retrofit consultants, 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 “retrofit consultants”. 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 retrofit consultants), 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 retrofit consultants, 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, 35,540 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 29, 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.
Retrofit consultants by metro
- Retrofit consultants in New York194
- Retrofit consultants in Houston80
- Retrofit consultants in Chicago60
- Retrofit consultants in San Francisco60
- Retrofit consultants in Los Angeles59
- Retrofit consultants in San Diego58
- Retrofit consultants in Atlanta46
- Retrofit consultants in Denver46
- Retrofit consultants in Miami46
- Retrofit consultants in Dallas42
- Retrofit consultants in Austin40
- Retrofit consultants in Portland40
- Retrofit consultants in Seattle36
- Retrofit consultants in Charlotte29
- Retrofit consultants in Tampa29
- Retrofit consultants in San Jose28
- Retrofit consultants in Phoenix27
- Retrofit consultants in San Antonio26
- Retrofit consultants in Philadelphia25
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 retrofit consultants, 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 retrofit consultants are there based in the United States?
RevenueBase identified 4,306 retrofit consultants 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?
Sargent & Lundy, headquartered in Casper, tops this list with the largest team on record.
Which city has the most retrofit consultants?
New York leads with 194 headquartered companies, followed by Houston (80) and Chicago (60).
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 35,540 verified decision-maker contacts tracked across these 4,306 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 29, 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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