Company lists · Data refreshed September 2026

Top 25 Greenhouse consulting firms based in the United States

Name: Greenhouse consulting 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 28, 2026 1,381 companies tracked

RevenueBase identified 1,381 greenhouse consulting firms headquartered in the United States as of September 2026 and tracks 14,011 professional contacts across them, including 5,628 with verified work emails. New York is the largest hub.

This list covers greenhouse consulting 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 28, 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 28, 2026 86% judged on-target in blind review

1,381Companies

14,011Contacts tracked

5,628Verified emails

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The 25 largest greenhouse consulting firms based in the United States

Ranked by team size

Top 25 of 1,381 greenhouse consulting firms based in the United States, ranked by team size, largest first. Data refreshed Sep 28, 2026. RevenueBase Smart Search rates how each company's information relates to greenhouse 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.
#	Company	RevenueBase Smart Search	Headquarters	Employees	Contacts
1	OLA	Partial evidence	Austin, TX, United StatesHQ checked Sep 28, 2026	n/a	1,145 contacts →
	Partial 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 28, 2026
2	Agritecture	Indirect evidence	New York, NY, United StatesHQ checked Sep 28, 2026	n/a	627 contacts →
	Indirect evidence “Agritecture is a global advisory firm specializing in climate-smart agriculture and controlled environment agriculture (CEA).” Source: RevenueBase Database · checked Sep 28, 2026
3	P2s	Indirect evidence	Long Beach, CA, United StatesHQ checked Sep 28, 2026	201-500	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 28, 2026
4	Environmental Consulting & Technology, Inc. ECT	Partial evidence	Gainesville, FL, United StatesHQ checked Sep 28, 2026	201-500	305 contacts →
	Partial evidence “Environmental Consulting & Technology, Inc.(ECT) is a multi-disciplinary environmental and sustainability consulting firm delivering strategy, permitting, design, and management…” Source: RevenueBase Database · checked Sep 28, 2026
5	Cascade Energy	Indirect evidence	Portland, OR, United StatesHQ checked Sep 28, 2026	201-500	288 contacts →
	Indirect evidence “At Cascade Energy, we believe in better.” Source: RevenueBase Database · checked Sep 28, 2026
6	Ecology And Environment, INC	Indirect evidence	Lancaster, NY, United StatesHQ checked Sep 28, 2026	5,001-10,000	278 contacts →
	Indirect evidence “E&E is now WSP USA.” Source: RevenueBase Database · checked Sep 28, 2026
7	PEG	Indirect evidence	Fairfax, VA, United StatesHQ checked Sep 28, 2026	201-500	214 contacts →
	Indirect evidence “PEG presents a comprehensive capacity for the evaluation and understanding of a broad base of energy and environmental sustainability related programs, policies and initiatives.” Source: RevenueBase Database · checked Sep 28, 2026
8	Bright Power	Indirect evidence	New York, NY, United StatesHQ checked Sep 28, 2026	51-200	205 contacts →
	Indirect evidence “Bright Power is a leading provider of energy efficiency and decarbonization solutions for the real estate industry.” Source: RevenueBase Database · checked Sep 28, 2026
9	Normandeau Associates, INC	Indirect evidence	Bedford, NH, United StatesHQ checked Sep 28, 2026	201-500	189 contacts →
	Indirect evidence Source: RevenueBase Database · checked Sep 28, 2026
10	Grumman Butkus Associates	Partial evidence	Evanston, IL, United StatesHQ checked Sep 28, 2026	51-200	153 contacts →
	Partial evidence “Grumman\|Butkus Associates (GBA) is a nationally recognized consulting engineering firm that specializes in mechanical, electrical and plumbing design services and energy and…” Source: RevenueBase Database · checked Sep 28, 2026
11	Steven Winter Associates	Indirect evidence	Norwalk, CT, United StatesHQ checked Sep 28, 2026	51-200	142 contacts →
	Indirect evidence “For over five decades, we’ve been at the forefront of transforming the built environment to be more energy efficient, accessible, healthy, and resilient.” Source: RevenueBase Database · checked Sep 28, 2026
12	STOK	Indirect evidence	San Francisco, CA, United StatesHQ checked Sep 28, 2026	51-200	141 contacts →
	Indirect evidence “Stok leads organizations to decarbonize now.” Source: RevenueBase Database · checked Sep 28, 2026
13	Four Seasons Environmental, INC	Indirect evidence	Monroe, OH, United StatesHQ checked Sep 28, 2026	201-500	134 contacts →
	Indirect evidence Source: RevenueBase Database · checked Sep 28, 2026
14	RE Tech Advisors	Indirect evidence	Mclean, VA, United StatesHQ checked Sep 28, 2026	51-200	124 contacts →
	Indirect evidence “RE Tech Advisors, a Legence Company, offers an integrated suite of solutions designed to drive building performance, decrease costs, and overcome any project challenge.” Source: RevenueBase Database · checked Sep 28, 2026
15	Michaels Energy- An Inc. 5000 Company	Partial evidence	La Crosse, WI, United StatesHQ checked Sep 28, 2026	51-200	121 contacts →
	Partial evidence “Michaels Energy is a veteran-owned energy consulting firm that exists to help businesses minimize waste and maximize value.” Source: RevenueBase Database · checked Sep 28, 2026
16	Agricultural Consulting Services	Indirect evidence	Ithaca, NY, United StatesHQ checked Sep 28, 2026	11-50	111 contacts →
	Indirect evidence “ACS helps farms to grow better crops and to maintain a strong environmental compliance position.” Source: RevenueBase Database · checked Sep 28, 2026
17	Cascadia Consulting Group	Partial evidence	Seattle, WA, United StatesHQ checked Sep 28, 2026	51-200	110 contacts →
	Partial evidence “Cascadia Consulting Group is a majority women-owned consulting firm specializing in environmental and sustainability solutions.” Source: RevenueBase Database · checked Sep 28, 2026
18	Ecoengineers	Partial evidence	Des Moines, IA, United StatesHQ checked Sep 28, 2026	51-200	109 contacts →
	Partial evidence “EcoEngineers, an LRQA company, is a consulting, auditing, and advisory firm with an exclusive focus on the energy transition and decarbonization.” Source: RevenueBase Database · checked Sep 28, 2026
19	Techlaw	Partial evidence	Chantilly, VA, United StatesHQ checked Sep 28, 2026	201-500	104 contacts →
	Partial evidence “Established in 1983, TechLaw provides environmental and management consulting services to the public sector nationwide.” Source: RevenueBase Database · checked Sep 28, 2026
20	Citadel EHS	Partial evidence	Glendale, CA, United StatesHQ checked Sep 28, 2026	51-200	102 contacts →
	Partial evidence “Founded in 1993, Citadel EHS provides comprehensive environmental, health, safety, and sustainability consulting solutions to meet the needs of both the public and private sectors.” Source: RevenueBase Database · checked Sep 28, 2026
21	Environ Energy	Indirect evidence	New York, NY, United StatesHQ checked Sep 28, 2026	51-200	98 contacts →
	Indirect evidence “Environ Energy is a leader in accelerating global sustainable energy transformation for more than 30 years.” Source: RevenueBase Database · checked Sep 28, 2026
22	KW Engineering	Indirect evidence	Oakland, CA, United StatesHQ checked Sep 28, 2026	51-200	97 contacts →
	Indirect evidence “In 1998, I started kW Engineering as a two-person firm with a singular vision: to become the leading technical experts at saving money in buildings by saving energy and water.” Source: RevenueBase Database · checked Sep 28, 2026
23	AKT Peerless	Indirect evidence	Saginaw, MI, United StatesHQ checked Sep 28, 2026	51-200	96 contacts →
	Indirect evidence “We are environmental consultants and redevelopment experts who are proud to help build sustainable communities.” Source: RevenueBase Database · checked Sep 28, 2026
24	Speedling Incorporated	Indirect evidence	Ruskin, FL, United StatesHQ checked Sep 28, 2026	51-200	92 contacts →
	Indirect evidence “At Speedling we are motivated by our customers’ success.” Source: RevenueBase Database · checked Sep 28, 2026
25	Verdani Partners	Partial evidence	Carlsbad, CA, United StatesHQ checked Sep 28, 2026	51-200	89 contacts →
	Partial evidence “Verdani Partners is a full service sustainability consulting firm specialized in corporate sustainability, LEED certification and greening and retrofitting existing buildings.” Source: RevenueBase Database · checked Sep 28, 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: greenhouse consulting 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 greenhouse consulting firms.
Partial evidence: Its own public description names part of greenhouse consulting firms, so it works in or next to the category without describing itself that way.
Indirect evidence: The description shown does not name greenhouse consulting 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 1,381 greenhouse consulting firms based in the United States

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Greenhouse consulting firms based in the United States at a glance

As of Sep 28, 2026

40.2%Verified-email coverage

10.1Average contacts per company

1-10Median size (employees)

3.9%Largest-city concentration · New York

Sep 28, 2026Page data refreshed

Companies by employee count

1-10

954

11-50

328

51-200

201-500

501-1,000

1,001-5,000

5,001-10,000

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 1,381 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 greenhouse 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 the United States whose own description of what they do matches “greenhouse 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 greenhouse 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 greenhouse consulting 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, 5,628 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 28, 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.

Greenhouse consulting 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 greenhouse 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 greenhouse consulting firms are there based in the United States?

RevenueBase identified 1,381 greenhouse consulting 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?

OLA, headquartered in Austin, tops this list with the largest team on record.

Which city has the most greenhouse consulting firms?

New York leads with 54 headquartered companies, followed by Chicago (36) and Denver (34).

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 5,628 verified decision-maker contacts tracked across these 1,381 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 28, 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.