Company lists · Data refreshed September 2026
Top 25 Infrastructure design firms based in Seattle, United States
RevenueBase identified 40 infrastructure design firms headquartered in Seattle, United States as of September 2026 and tracks 5,505 professional contacts across them, including 3,760 with verified work emails. Houston is the largest hub.
This list covers infrastructure design firms headquartered in Seattle, 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 20, 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 infrastructure design firms based in Seattle, United States
Ranked by team size| # | Company | Contacts | |||
|---|---|---|---|---|---|
| 1 | 1,487 contacts → | ||||
Indirect evidence “KPFF is a multi-office, multi-discipline engineering firm.” Source: RevenueBase Database · checked Sep 20, 2026Thanks. The Data Team will review it. | |||||
| 2 | 880 contacts → | ||||
Indirect evidence “At Parametrix, we help our clients imagine what's possible.” Source: RevenueBase Database · checked Sep 20, 2026Thanks. The Data Team will review it. | |||||
| 3 | 859 contacts → | ||||
Indirect evidence “The right team is more than an advantage.” Source: RevenueBase Database · checked Sep 20, 2026Thanks. The Data Team will review it. | |||||
| 4 | 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 20, 2026Thanks. The Data Team will review it. | |||||
| 5 | 311 contacts → | ||||
Indirect evidence “Delve Underground is a leader in heavy civil engineering, serving the transportation, water, wastewater, and energy industries.” Source: RevenueBase Database · checked Sep 20, 2026Thanks. The Data Team will review it. | |||||
| 6 | 287 contacts → | ||||
Partial evidence “Mithun is an integrated design firm dedicated to creating positive change in people’s lives.” Source: RevenueBase Database · checked Sep 20, 2026Thanks. The Data Team will review it. | |||||
| 7 | 190 contacts → | ||||
Indirect evidence “We engineer the future of the built environment, one structure, skyline, and community at a time.” Source: RevenueBase Database · checked Sep 20, 2026Thanks. The Data Team will review it. | |||||
| 8 | 178 contacts → | ||||
Indirect evidence “Harris Group is a multidiscipline engineering consulting firm with offices located throughout the United States.” Source: RevenueBase Database · checked Sep 20, 2026Thanks. The Data Team will review it. | |||||
| 9 | 170 contacts → | ||||
Partial evidence “About LMN Architects Seattle-based LMN Architects specializes in the planning and design of significant public and private facilities, including convention centers, cultural arts…” Source: RevenueBase Database · checked Sep 20, 2026Thanks. The Data Team will review it. | |||||
| 10 | 126 contacts → | ||||
Indirect evidence Source: RevenueBase Database · checked Sep 20, 2026Thanks. The Data Team will review it. | |||||
| 11 | 115 contacts → | ||||
Partial evidence “GGLO is an integrated design firm that provides architecture, urban design, planning, research, interior design, and landscape architecture to clients around the world.” Source: RevenueBase Database · checked Sep 20, 2026Thanks. The Data Team will review it. | |||||
| 12 | 99 contacts → | ||||
Indirect evidence “Municipal Engineering Services” Source: RevenueBase Database · checked Sep 20, 2026Thanks. The Data Team will review it. | |||||
| 13 | 66 contacts → | ||||
Partial evidence “KPG was initially formed in 1990 by a team of engineers, architects, landscape architects, and urban designers committed to and focused on community-driven public projects.” Source: RevenueBase Database · checked Sep 20, 2026Thanks. The Data Team will review it. | |||||
| 14 | 65 contacts → | ||||
Partial evidence “Andersen Bjornstad Kane Jacobs (ABKJ) is a premier consulting design firm in the United States.” Source: RevenueBase Database · checked Sep 20, 2026Thanks. The Data Team will review it. | |||||
| 15 | 37 contacts → | ||||
Partial evidence “Board & Vellum is a multidisciplinary design firm based on Capitol Hill in Seattle, offering architecture, interior design, and landscape architecture for residential, commercial…” Source: RevenueBase Database · checked Sep 20, 2026Thanks. The Data Team will review it. | |||||
| 16 | 34 contacts → | ||||
Partial evidence “HBB is a 20 person professional Landscape Architecture, Urban Design, and Planning firm located in Downtown Seattle.” Source: RevenueBase Database · checked Sep 20, 2026Thanks. The Data Team will review it. | |||||
| 17 | 29 contacts → | ||||
Partial evidence “SvR Design Company was founded in 1989 with a mission of providing innovation in the built environment.” Source: RevenueBase Database · checked Sep 20, 2026Thanks. The Data Team will review it. | |||||
| 18 | 22 contacts → | ||||
Partial evidence “WJA Design Collaborative, established in 1968 as Whiteley Jacobsen Associates, has provided architectural and engineering services to Federal clients and private contractors…” Source: RevenueBase Database · checked Sep 20, 2026Thanks. The Data Team will review it. | |||||
| 19 | 19 contacts → | ||||
Partial evidence “Improving our communities through economical, functional and sustainable civil design solutions.” Source: RevenueBase Database · checked Sep 20, 2026Thanks. The Data Team will review it. | |||||
| 20 | 17 contacts → | ||||
Indirect evidence Source: RevenueBase Database · checked Sep 20, 2026Thanks. The Data Team will review it. | |||||
| 21 | 16 contacts → | ||||
Partial evidence “Integrated Design Engineers (idE) is a Seattle-based structural engineering consulting firm founded in 2005.” Source: RevenueBase Database · checked Sep 20, 2026Thanks. The Data Team will review it. | |||||
| 22 | 12 contacts → | ||||
Indirect evidence “HAINLINE was founded in 1981 to assist owners, architects, and contractors in the construction process.” Source: RevenueBase Database · checked Sep 20, 2026Thanks. The Data Team will review it. | |||||
| 23 | 8 contacts → | ||||
Partial evidence “RHC Engineering is specialized in bridge and structural design.” Source: RevenueBase Database · checked Sep 20, 2026Thanks. The Data Team will review it. | |||||
| 24 | 8 contacts → | ||||
Partial evidence “OUR FIRM We're a Seattle based Civil Engineering Firm focused on superior service accompanied with cutting edge analysis and design capabilities.” Source: RevenueBase Database · checked Sep 20, 2026Thanks. The Data Team will review it. | |||||
| 25 | 7 contacts → | ||||
Partial evidence “TFWB Engineers formerly Travis, Fitzmaurice & Associates is an electrical, telecommunications, and security design consulting firm.” Source: RevenueBase Database · checked Sep 20, 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: infrastructure design 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 infrastructure design firms.
- Partial evidence
- Its own public description names part of infrastructure design firms, so it works in or next to the category without describing itself that way.
- Indirect evidence
- The description shown does not name infrastructure design 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 40 infrastructure design firms based in Seattle, United States
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Infrastructure design firms based in Seattle, United States at a glance
As of Sep 20, 2026Companies by employee count
Email recency for this list is measured across the whole United States list rather than for Seattle, so it is reported there. Company counts and contact totals on this page are exact for Seattle, over 40 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 infrastructure design 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 Seattle, United States whose own description of what they do matches “infrastructure design 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 infrastructure design 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 infrastructure design firms, and records with no verified work email. Companies headquartered outside Seattle 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, 3,760 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 20, 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.
Infrastructure design firms by metro in the United States
- Infrastructure design firms in Houston156
- Infrastructure design firms in New York141
- Infrastructure design firms in Chicago89
- Infrastructure design firms in Miami71
- Infrastructure design firms in Dallas70
- Infrastructure design firms in Austin67
- Infrastructure design firms in Los Angeles62
- Infrastructure design firms in Atlanta56
- Infrastructure design firms in San Francisco55
- Infrastructure design firms in Orlando54
- Infrastructure design firms in Tampa54
- Infrastructure design firms in Washington52
- Infrastructure design firms in Raleigh49
- Infrastructure design firms in San Diego49
- Infrastructure design firms in Phoenix46
- Infrastructure design firms in San Antonio44
- Infrastructure design firms in Portland42
- Infrastructure design firms in Seattle40
- Infrastructure design firms in Denver38
- Infrastructure design firms in Jacksonville38
- Infrastructure design firms in Irvine36
- Infrastructure design firms in Boston34
- Infrastructure design firms in Charlotte34
- Infrastructure design firms in Columbus32
- Infrastructure design firms in Indianapolis32
- Infrastructure design firms in Las Vegas29
- Infrastructure design firms in Nashville29
- Infrastructure design firms in Pittsburgh26
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 infrastructure design 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 infrastructure design firms are there based in Seattle, United States?
RevenueBase identified 40 infrastructure design firms headquartered in Seattle, 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?
Kpff Consulting Engineers, headquartered in Seattle, tops this list with the largest team on record.
Which city has the most infrastructure design firms?
Houston leads with 156 headquartered companies, followed by New York (141) and Chicago (89).
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 3,760 verified decision-maker contacts tracked across these 40 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 20, 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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