Company lists · Data refreshed September 2026

Top 25 Retrofit contractors worldwide

Name: Retrofit contractors worldwide
Creator: RevenueBase
License: https://creativecommons.org/licenses/by/4.0/

Compiled by the RevenueBase Data Team Data refreshed Sep 17, 2026 12,356 companies tracked

RevenueBase identified 12,356 retrofit contractors worldwide as of September 2026 and tracks 175,344 professional contacts across them, including 46,349 with verified work emails and 0 with mobile numbers. The United States is the largest market and New York the largest hub.

This list covers retrofit contractors worldwide, 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 17, 2026. Country and city lists for retrofit contractors follow the table.

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 17, 2026 86% judged on-target in blind review

12,356Companies

175,344Contacts tracked

46,349Verified emails

0Mobile numbers

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The 25 largest retrofit contractors worldwide

Ranked by team size

Top 25 of 12,356 retrofit contractors worldwide, ranked by team size, largest first. Data refreshed Sep 17, 2026. RevenueBase Smart Search rates how each company's information relates to retrofit contractors: 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	Johnson Controls	Indirect evidence	Cork, IrelandHQ checked Sep 17, 2026	10001+	52,736 contacts →
	Indirect evidence “Johnson Controls is a global leader in thermal management, mission-critical building systems, energy efficiency and decarbonization.” Source: RevenueBase Database · checked Sep 17, 2026
2	Mckinstry	Indirect evidence	Seattle, WA, United StatesHQ checked Sep 17, 2026	1,001-5,000	2,213 contacts →
	Indirect evidence “We're a national construction and energy services company dedicated to innovating the waste and climate harm out of the built environment.” Source: RevenueBase Database · checked Sep 17, 2026
3	Ameresco	Indirect evidence	Framingham, MA, United StatesHQ checked Sep 17, 2026	1,001-5,000	1,383 contacts →
	Indirect evidence “Ameresco, Inc.(NYSE:AMRC) is a leading energy infrastructure solutions provider dedicated to helping customers reduce costs, enhance resilience, and decarbonize to net zero in the…” Source: RevenueBase Database · checked Sep 17, 2026
4	GK	Indirect evidence	Oslo, NorwayHQ checked Sep 17, 2026	1,001-5,000	1,150 contacts →
	Indirect evidence “GK er en ledende teknisk entreprenør og servicepartner.” Source: RevenueBase Database · checked Sep 17, 2026
5	Lindner Group	Indirect evidence	Arnstorf, GermanyHQ checked Sep 17, 2026	5,001-10,000	1,129 contacts →
	Indirect evidence “The Lindner Group is Europe's leading full-service provider - manufacturer and service provider - for interior fit-out, building envelope, building services and insulation…” Source: RevenueBase Database · checked Sep 17, 2026
6	Kingspan Insulation	Indirect evidence	Leominster, United StatesHQ checked Sep 17, 2026	1,001-5,000	955 contacts →
	Indirect evidence “Kingspan Insulation is the industry leading manufacturer of innovative insulation solutions, which help create a more sustainable and energy efficient built environment.” Source: RevenueBase Database · checked Sep 17, 2026
7	Climatec, LLC	Indirect evidence	Phoenix, AZ, United StatesHQ checked Sep 17, 2026	1,001-5,000	863 contacts →
	Indirect evidence “Climatec has been making buildings safer, more comfortable and efficient for over 40 years.” Source: RevenueBase Database · checked Sep 17, 2026
8	Feenstra	Indirect evidence	Lelystad, NetherlandsHQ checked Sep 17, 2026	1,001-5,000	781 contacts →
	Indirect evidence “Sinds het ontstaan in 1947 is Feenstra marktleider in installatietechniek met een nationale dekking.” Source: RevenueBase Database · checked Sep 17, 2026
9	SEL Construction Corporation	Partial evidence	Loomis, CA, United StatesHQ checked Sep 17, 2026	n/a	722 contacts →
	Partial evidence “Experienced commercial contractor specializing in renewable energy, electrical, and roofing projects for privately-owned buildings as well as state/local government buildings in…” Source: RevenueBase Database · checked Sep 17, 2026
10	Baker Group	Partial evidence	Ankeny, IA, United StatesHQ checked Sep 17, 2026	1,001-5,000	655 contacts →
	Partial 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 17, 2026
11	Alterman, INC	Indirect evidence	Live Oak, TX, United StatesHQ checked Sep 17, 2026	501-1,000	597 contacts →
	Indirect evidence “Since 1923, Alterman has provided electrical construction on many of San Antonio and Austin's most impressive landmarks and contemporary structures.” Source: RevenueBase Database · checked Sep 17, 2026
12	Murphy Company	Partial evidence	St. Louis, MO, United StatesHQ checked Sep 17, 2026	1,001-5,000	579 contacts →
	Partial evidence “Per Colorado State Law Our CO Plumbing Contractor License Our Master Plumbing License is MP.03001288.” Source: RevenueBase Database · checked Sep 17, 2026
13	Technitoit	Indirect evidence	Les Ponts De Cé, FranceHQ checked Sep 17, 2026	501-1,000	519 contacts →
	Indirect evidence “Notre groupe, premier fabricant-applicateur, est le spécialiste français de l'amélioration de l'habitat.” Source: RevenueBase Database · checked Sep 17, 2026
14	Pieper Electric, INC	Indirect evidence	New Berlin, WI, United StatesHQ checked Sep 17, 2026	501-1,000	498 contacts →
	Indirect evidence “At Pieper Electric, Inc,"Our People Are Our Power" isn't just a phrase; it's our way of life.” Source: RevenueBase Database · checked Sep 17, 2026
15	Noresco	Indirect evidence	Westborough, MA, United StatesHQ checked Sep 17, 2026	201-500	481 contacts →
	Indirect evidence “NORESCO, a part of Carrier Global Corporation, helps customers modernize aging building systems and upgrade energy and water infrastructure to meet evolving demands.” Source: RevenueBase Database · checked Sep 17, 2026
16	Carlisle Companies Incorporated	Indirect evidence	Scottsdale, AZ, United StatesHQ checked Sep 17, 2026	5,001-10,000	472 contacts →
	Indirect evidence “Carlisle Companies Incorporated is a leading supplier of innovative building envelope products and solutions for more energy efficient buildings.” Source: RevenueBase Database · checked Sep 17, 2026
17	Sitelogiq	Indirect evidence	Minneapolis, MN, United StatesHQ checked Sep 17, 2026	501-1,000	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 17, 2026
18	Jmeg Electrical Contractors	Indirect evidence	Farmers Branch, TX, United StatesHQ checked Sep 17, 2026	501-1,000	437 contacts →
	Indirect evidence “JMEG is a team of professionals who have been providing electrical construction services for over 35 years throughout the state of Texas.” Source: RevenueBase Database · checked Sep 17, 2026
19	Romanoff Group	Indirect evidence	Gahanna, OH, United StatesHQ checked Sep 17, 2026	1,001-5,000	431 contacts →
	Indirect evidence “The Romanoff Group of Companies has been dedicated to providing specialized electrical, plumbing, and heating and cooling services since 1992.” Source: RevenueBase Database · checked Sep 17, 2026
20	Shankar Electricals Services I Private Limited	Partial evidence	Bangalore, IndiaHQ checked Sep 17, 2026	1,001-5,000	425 contacts →
	Partial evidence “We are the leading MEP Contractor & Consultant with extensive knowledge in the Projects and O&M Services, having executed several Projects for fortune 500 companies and providing…” Source: RevenueBase Database · checked Sep 17, 2026
21	John W. Danforth Company	Indirect evidence	Tonawanda, NY, United StatesHQ checked Sep 17, 2026	501-1,000	415 contacts →
	Indirect evidence “We are powered by the best people in the industry.” Source: RevenueBase Database · checked Sep 17, 2026
22	FR Instalações E Construções Ltda	Indirect evidence	Sao Paulo, BrazilHQ checked Sep 17, 2026	1,001-5,000	399 contacts →
	Indirect evidence “A FR Instalações é uma empresa especializada em instalações elétricas, hidráulicas, mecânicas e combate a incêndio de empreendimentos residenciais, comerciais, industriais e…” Source: RevenueBase Database · checked Sep 17, 2026
23	OZZ Electric INC	Partial evidence	Concord, ON, United StatesHQ checked Sep 17, 2026	1,001-5,000	396 contacts →
	Partial evidence “Celebrating our 35th year in business, OZZ Electric is a leading full service electrical contractor, specializing in large scale projects as well as high profile design/build work.” Source: RevenueBase Database · checked Sep 17, 2026
24	Strada Services	Indirect evidence	Sanford, FL, United StatesHQ checked Sep 17, 2026	1,001-5,000	391 contacts →
	Indirect evidence “Strada Services is a full service electrical, security, and air conditioning contracting company servicing residential, commercial, and industrial customers in Florida and in the…” Source: RevenueBase Database · checked Sep 17, 2026
25	Veregy	Indirect evidence	Phoenix, MO, United StatesHQ checked Sep 17, 2026	501-1,000	383 contacts →
	Indirect evidence “Veregy is an award-winning NAESCO-Accredited decarbonization company focusing on accelerating and simplifying the Energy Transition.” Source: RevenueBase Database · checked Sep 17, 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: retrofit contractors. 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 contractors.
Partial evidence: Its own public description names part of retrofit contractors, so it works in or next to the category without describing itself that way.
Indirect evidence: The description shown does not name retrofit contractors. 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 12,356 retrofit contractors worldwide

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Retrofit contractors worldwide at a glance

As of Sep 17, 2026

26.4%Verified-email coverage

14.2Average contacts per company

11-50Median size (employees)

1.0%Largest-city concentration · New York

Sep 17, 2026Page data refreshed

Companies by employee count

1-10

5,931

11-50

4,538

51-200

1,387

201-500

241

501-1,000

1,001-5,000

5,001-10,000

10001+

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 contractors, 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.
Coverage: 26 countries, largest first: the United States, France, Canada, the United Kingdom, Italy, the Netherlands, Spain, Germany, Brazil, Australia and 16 more. Country and city lists for retrofit contractors are linked below.
What qualifies: Companies worldwide whose own description of what they do matches “retrofit contractors”. 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 contractors), 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 contractors, and records with no verified work email.
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, 46,349 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 17, 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 contractors by location

47 lists · largest first

Every Retrofit contractors list RevenueBase publishes, by country and city. Counts are matching companies in each list as of its own refresh date.

Countries

Cities

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 contractors, 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 contractors are there worldwide?

RevenueBase identified 12,356 retrofit contractors worldwide 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?

Johnson Controls, headquartered in Milwaukee, tops this list with the largest team on record.

Which country has the most retrofit contractors?

The United States leads with 5,218 companies, followed by France (1,373) and Canada (983). Every retrofit contractors list by country and city is linked on this page.

Which city has the most retrofit contractors?

New York leads with 129 headquartered companies, followed by London (110) and Sao Paulo (95).

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 46,349 verified decision-maker contacts tracked across these 12,356 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 17, 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.