Company lists · Data refreshed September 2026

Top 25 Sustainability consulting firms based in Chicago, United States

RevenueBase identified 83 sustainability consulting firms headquartered in Chicago, United States as of September 2026 and tracks 889 professional contacts across them, including 307 with verified work emails. New York is the largest hub.

This list covers sustainability consulting firms headquartered in Chicago, 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 6, 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 6, 2026 86% judged on-target in blind review
83Companies
889Contacts tracked
307Verified emails
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The 25 largest sustainability consulting firms based in Chicago, United States

Ranked by team size
Top 25 of 83 sustainability consulting firms based in Chicago, United States, ranked by team size, largest first. Data refreshed Sep 6, 2026. RevenueBase Smart Search rates how each company's information relates to sustainability consulting 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.
#CompanyRevenueBase Smart SearchHeadquartersEmployeesContacts
1Strong evidenceChicago, IL, United StatesHQ checked Sep 6, 202651-200183 contacts →

“SUMAC is an architecture, engineering, and consulting firm that promotes sustainability as the key element to increasing the profitability of our clients and partners.”

Source: company website · checked Sep 6, 2026
2Indirect evidenceChicago, IL, United StatesHQ checked Sep 6, 202651-20097 contacts →

“BBJ provides clients with solutions to environmental, health and safety problems.”

Source: company website · checked Sep 6, 2026
3Partial evidenceChicago, IL, United StatesHQ checked Sep 6, 202611-5064 contacts →

“WRD Environmental helps organizations committed to sustainability realize their vision.”

Source: company website · checked Sep 6, 2026
4Partial evidenceChicago, IL, United StatesHQ checked Sep 6, 202611-5056 contacts →

“With roots dating back more than 100 years, FitzGerald is a national architecture, interior design, and sustainability firm committed to the creation of exemplary environments…”

Source: company website · checked Sep 6, 2026
5Indirect evidenceChicago, IL, United StatesHQ checked Sep 6, 202611-5052 contacts →

“Carnow, Conibear & Assoc, Ltd.(Carnow Conibear), a minority-owned, woman-owned and veteran-owned business, was established in 1975.”

Source: company website · checked Sep 6, 2026
6Strong evidenceChicago, IL, United StatesHQ checked Sep 6, 202611-5043 contacts →

“Aeterra is a full-service environmental and sustainability consulting firm that provides operating businesses and their owners with meaningful, practical, business-focused advice.”

Source: company website · checked Sep 6, 2026
7Indirect evidenceChicago, IL, United StatesHQ checked Sep 6, 202611-5042 contacts →

“Carbon Solutions Group was founded in Chicago, Illinois, in 2006.”

Source: company website · checked Sep 6, 2026
8Strong evidenceChicago, IL, United StatesHQ checked Sep 6, 202611-5034 contacts →

“The Center for Sustainability and Excellence (CSE) is a global leader in ESG consulting, Net Zero strategy, and Circular Economy solutions.”

Source: company website · checked Sep 6, 2026
9Strong evidenceChicago, IL, United StatesHQ checked Sep 6, 202611-5030 contacts →

“National Retrofitting Group provides sustainability consulting along with a variety of energy retrofitting services to help our customers save money on their energy bills while…”

Source: company website · checked Sep 6, 2026
10Indirect evidenceChicago, IL, United StatesHQ checked Sep 6, 202611-5017 contacts →

“Carlson Environmental, a Nova Group, GBC Company, was originally founded in 1988 by Dr.”

Source: company website · checked Sep 6, 2026
11Indirect evidenceChicago, IL, United StatesHQ checked Sep 6, 202611-5014 contacts →

“Eco Achievers helps property owners smartly transform their buildings into healthy, resilient and efficient places.”

Source: company website · checked Sep 6, 2026
12Partial evidenceChicago, IL, United StatesHQ checked Sep 6, 20261-1013 contacts →

“Strategic Growth Consulting helps small to medium sized professional service companies identify, plan and execute growth strategies bringing over 30 years of experience in the…”

Source: company website · checked Sep 6, 2026
13Indirect evidenceChicago, IL, United StatesHQ checked Sep 6, 20261-1012 contacts →

“Captios Partners is a professional services and engineering consultancy dedicated to bringing global resources and businesses together to create quality product strategies…”

Source: company website · checked Sep 6, 2026
14Indirect evidenceChicago, IL, United StatesHQ checked Sep 6, 202611-509 contacts →

“HUSARCH collaborates with architectural, energy, and construction industry leaders to develop actionable, data driven solutions.”

Source: company website · checked Sep 6, 2026
15Partial evidenceChicago, IL, United StatesHQ checked Sep 6, 202611-508 contacts →

“As a global full-service sustainability agency, we help organisations stay eligible for markets, capital, and regulation by turning sustainability into a source of resilience…”

Source: company website · checked Sep 6, 2026
16Strong evidenceChicago, IL, United StatesHQ checked Sep 6, 20261-107 contacts →

“Inova Energy Group is a certified WBE offering management consulting, strategic planning, and project delivery solutions in the areas of energy and sustainability.”

Source: company website · checked Sep 6, 2026
17Indirect evidenceChicago, IL, United StatesHQ checked Sep 6, 202611-507 contacts →

“The Astor Company opened its doors almost 20 years ago as a cardboard recycling company, beginning a journey of continuous adaptation and evolution which today finds a world-class…”

Source: company website · checked Sep 6, 2026
18Indirect evidenceChicago, IL, United StatesHQ checked Sep 6, 20261-106 contacts →

“Operators supporting operators.”

Source: company website · checked Sep 6, 2026
19Partial evidenceChicago, IL, United StatesHQ checked Sep 6, 20261-105 contacts →

“Celebrating 10 years of service in 2026, Climate Resilience Consulting helps states, cities and small businesses turn climate risk into resilience.”

Source: company website · checked Sep 6, 2026
20Indirect evidenceChicago, IL, United StatesHQ checked Sep 6, 20261-105 contacts →

“E4 LLC is a trusted advisor to C&I and municipal clients navigating the evolving clean energy landscape.”

Source: company website · checked Sep 6, 2026
21Partial evidenceChicago, IL, United StatesHQ checked Sep 6, 20261-105 contacts →

“Kairos Worldwide is a proven leader in process engineering consulting and is dedicated to reducing waste and enabling robust, sustainable growth for all types of clients.”

Source: company website · checked Sep 6, 2026
22Indirect evidenceChicago, IL, United StatesHQ checked Sep 6, 20261-104 contacts →

“APMonarch is a Chicago based architecture firm with the ethos to design healthier buildings and equitable communities.”

Source: company website · checked Sep 6, 2026
23Partial evidenceChicago, IL, United StatesHQ checked Sep 6, 202611-504 contacts →

“Environmental Group Services, Ltd.(EGSL) is a full service environmental engineering, training and consulting company located in Chicago, Illinois.”

Source: company website · checked Sep 6, 2026
24Partial evidenceChicago, IL, United StatesHQ checked Sep 6, 20261-103 contacts →

“Greenleaf Advisors is a consulting and transaction-services firm that builds sustainable enterprises and communities by bridging them to the resources and strategies they need to…”

Source: company website · checked Sep 6, 2026
25Indirect evidenceChicago, IL, United StatesHQ checked Sep 6, 202611-503 contacts →

“Awarded Inc's 2022 and 2023 #PowerPartner Award!”

Source: company website · checked Sep 6, 2026

Showing 25 of 83 sustainability consulting firms based in Chicago, United States

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Sustainability consulting firms based in Chicago, United States at a glance

As of Sep 6, 2026
34.5%Verified-email coverage
10.7Average contacts per company
1-10Median size (employees)
214.5%Largest-city concentration · New York
Sep 6, 2026Page data refreshed

Companies by employee count

1-10
56
11-50
22
51-200
3
1,001-5,000
1
10001+
1

Email recency for this list is measured across the whole United States list rather than this city, so it is reported there. Company counts and contact totals on this page are exact for Chicago, over 83 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 sustainability consulting 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 Chicago, United States whose own description of what they do matches “sustainability consulting 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 sustainability consulting 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 sustainability consulting firms, and records with no verified work email. Companies headquartered outside Chicago 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, 307 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 6, 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 sustainability consulting 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 sustainability consulting firms are there based in Chicago, United States?

RevenueBase identified 83 sustainability consulting firms headquartered in Chicago, 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?

SUMAC, headquartered in Chicago, tops this list with the largest team on record.

Which city has the most sustainability consulting firms?

New York leads with 178 headquartered companies, followed by Houston (97) and Los Angeles (90).

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 307 verified decision-maker contacts tracked across these 83 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 6, 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.