Company lists · Data refreshed September 2026
Top 25 Building energy retrofit consultants based in the United States
RevenueBase identified 1,468 building energy retrofit consultants headquartered in the United States as of September 2026 and tracks 19,907 professional contacts across them, including 8,350 with verified work emails. New York is the largest hub.
This list covers building energy 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 27, 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 building energy retrofit consultants based in the United States
Ranked by team size| # | Company | Contacts | |||
|---|---|---|---|---|---|
| 1 | 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 27, 2026Thanks. The Data Team will review it. | |||||
| 2 | 851 contacts → | ||||
Indirect evidence “Willdan (NASDAQ: WLDN) provides professional consulting and technical services to utilities, public agencies and private industry throughout the United States.” Source: RevenueBase Database · checked Sep 27, 2026Thanks. The Data Team will review it. | |||||
| 3 | 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 27, 2026Thanks. The Data Team will review it. | |||||
| 4 | 386 contacts → | ||||
Partial 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 27, 2026Thanks. The Data Team will review it. | |||||
| 5 | 383 contacts → | ||||
Partial evidence “We are Trio – built from Edison Energy, Alfa Energy, and Altenex Energy.” Source: RevenueBase Database · checked Sep 27, 2026Thanks. The Data Team will review it. | |||||
| 6 | 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 27, 2026Thanks. The Data Team will review it. | |||||
| 7 | 356 contacts → | ||||
Partial evidence “At HomeWorks Energy, our mission is simple, literally: Energy Efficiency, Simplified.” Source: RevenueBase Database · checked Sep 27, 2026Thanks. The Data Team will review it. | |||||
| 8 | 355 contacts → | ||||
Partial 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 27, 2026Thanks. The Data Team will review it. | |||||
| 9 | 336 contacts → | ||||
Indirect evidence “National Utility Service, Inc.” Source: RevenueBase Database · checked Sep 27, 2026Thanks. The Data Team will review it. | |||||
| 10 | 288 contacts → | ||||
Partial evidence “At Cascade Energy, we believe in better.” Source: RevenueBase Database · checked Sep 27, 2026Thanks. The Data Team will review it. | |||||
| 11 | 233 contacts → | ||||
Partial evidence “At Mantis Innovation, our experts provide data-driven, consultative services designed to optimize your facility, sustainability, and energy management strategies, while ultimately…” Source: RevenueBase Database · checked Sep 27, 2026Thanks. The Data Team will review it. | |||||
| 12 | 233 contacts → | ||||
Indirect evidence “As of November of 2025, AMA Group has merged with CMTA!” Source: RevenueBase Database · checked Sep 27, 2026Thanks. The Data Team will review it. | |||||
| 13 | 229 contacts → | ||||
Strong evidence “Allana Buick & Bers, Inc.(ABB) is a leading Architectural Engineering firm specializing in making buildings perform better by making them energy efficient and longer lasting with…” Source: RevenueBase Database · checked Sep 27, 2026Thanks. The Data Team will review it. | |||||
| 14 | 214 contacts → | ||||
Partial 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 27, 2026Thanks. The Data Team will review it. | |||||
| 15 | 210 contacts → | ||||
Partial evidence “Dalkia Energy Solutions, a subsidiary of the EDF (Électricité de France) Group, is a national leader in energy efficiency and sustainability for commercial, industrial, and…” Source: RevenueBase Database · checked Sep 27, 2026Thanks. The Data Team will review it. | |||||
| 16 | 205 contacts → | ||||
Partial evidence “Bright Power is a leading provider of energy efficiency and decarbonization solutions for the real estate industry.” Source: RevenueBase Database · checked Sep 27, 2026Thanks. The Data Team will review it. | |||||
| 17 | 193 contacts → | ||||
Partial evidence “EMC manages and scales turnkey energy efficiency solutions for Fortune 500 clients across their North American portfolios.” Source: RevenueBase Database · checked Sep 27, 2026Thanks. The Data Team will review it. | |||||
| 18 | 192 contacts → | ||||
Partial evidence “Frontier Energy is a professional services firm that excels in market transformation.” Source: RevenueBase Database · checked Sep 27, 2026Thanks. The Data Team will review it. | |||||
| 19 | 166 contacts → | ||||
Partial evidence “Headquartered in Harrisburg, Pennsylvania, McClure Company is one of the mid-Atlantic's largest, fully integrated mechanical construction, engineering, maintenance and energy…” Source: RevenueBase Database · checked Sep 27, 2026Thanks. The Data Team will review it. | |||||
| 20 | 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 27, 2026Thanks. The Data Team will review it. | |||||
| 21 | 151 contacts → | ||||
Partial evidence “RISE is a pioneer in the delivery of turnkey energy-efficiency services for residential, commercial and industrial facilities.” Source: RevenueBase Database · checked Sep 27, 2026Thanks. The Data Team will review it. | |||||
| 22 | 142 contacts → | ||||
Partial 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 27, 2026Thanks. The Data Team will review it. | |||||
| 23 | 135 contacts → | ||||
Indirect evidence Source: RevenueBase Database · checked Sep 27, 2026Thanks. The Data Team will review it. | |||||
| 24 | 134 contacts → | ||||
Indirect evidence Source: RevenueBase Database · checked Sep 27, 2026Thanks. The Data Team will review it. | |||||
| 25 | 134 contacts → | ||||
Indirect evidence “Sain Engineering Associates, Inc.(SEA) is a U.S.” Source: RevenueBase Database · checked Sep 27, 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: building energy 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 building energy retrofit consultants.
- Partial evidence
- Its own public description names part of building energy retrofit consultants, so it works in or next to the category without describing itself that way.
- Indirect evidence
- The description shown does not name building energy 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 1,468 building energy retrofit consultants based in the United States
See the full list, filter by size, metro and specialty, and get verified emails and direct dials for all 8,350 reachable decision-makers.
Free signup · no credit card
Building energy retrofit consultants based in the United States at a glance
As of Sep 27, 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 1,468 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 energy 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 “building energy 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 building energy 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 building energy 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, 8,350 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 27, 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 energy retrofit consultants 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 energy 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 building energy retrofit consultants are there based in the United States?
RevenueBase identified 1,468 building energy 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?
OLA, headquartered in Austin, tops this list with the largest team on record.
Which city has the most building energy retrofit consultants?
New York leads with 67 headquartered companies, followed by Denver (27) and Chicago (26).
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 8,350 verified decision-maker contacts tracked across these 1,468 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 27, 2026.
Ready to reach these companies? Verified emails and direct dials for all 1,468 building energy retrofit consultants based in the United States. Start with a free account, no credit card.
Download this list →Related lists
Building energy retrofit consultants by geography
- Building energy retrofit consultants based in Chicago, United States
- Building energy retrofit consultants based in Denver, United States
- Building energy retrofit consultants based in New York, United States
- Building energy retrofit consultants based in Australia
- Building energy retrofit consultants based in Austria
- Building energy retrofit consultants based in Belgium
- Building energy retrofit consultants based in Brazil
- Building energy retrofit consultants based in Canada
- Building energy retrofit consultants based in Chile
- Building energy retrofit consultants based in Denmark
- Building energy retrofit consultants based in France
- Building energy retrofit consultants based in Germany
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.
More company lists
- All company lists
- Lists by location
- Lists A-Z
- New lists
- Building energy retrofit consultants based in Chicago, United States
- Building energy retrofit consultants based in Denver, United States
- Building energy retrofit consultants based in New York, United States
- Building energy retrofit consultants based in Australia
- Building energy retrofit consultants based in Austria
- Building energy retrofit consultants based in Belgium