Company lists · Data refreshed September 2026

Top 25 Sustainable design firms based in Seattle, United States

Name: Sustainable design firms based in Seattle, United States
Creator: RevenueBase
License: https://creativecommons.org/licenses/by/4.0/

Compiled by the RevenueBase Data Team Data refreshed Sep 22, 2026 121 companies tracked

RevenueBase identified 121 sustainable design firms headquartered in Seattle, United States as of September 2026 and tracks 2,879 professional contacts across them, including 1,704 with verified work emails. New York is the largest hub.

This list covers sustainable 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 22, 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 22, 2026 86% judged on-target in blind review

121Companies

2,879Contacts tracked

1,704Verified emails

Explore this list → Free signup · no credit card · 500 free credits

The 25 largest sustainable design firms based in Seattle, United States

Ranked by team size

Top 25 of 121 sustainable design firms based in Seattle, United States, ranked by team size, largest first. Data refreshed Sep 22, 2026. RevenueBase Smart Search rates how each company's information relates to sustainable design 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	Parametrix	Indirect evidence	Seattle, WA, United StatesHQ checked Sep 22, 2026	501-1,000	880 contacts →
	Indirect evidence “At Parametrix, we help our clients imagine what's possible.” Source: RevenueBase Database · checked Sep 22, 2026
2	Mithun	Partial evidence	Seattle, WA, United StatesHQ checked Sep 22, 2026	51-200	287 contacts →
	Partial evidence “Mithun is an integrated design firm dedicated to creating positive change in people’s lives.” Source: RevenueBase Database · checked Sep 22, 2026
3	LMN Architects	Partial evidence	Seattle, WA, United StatesHQ checked Sep 22, 2026	51-200	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 22, 2026
4	Gglo Design	Partial evidence	Seattle, WA, United StatesHQ checked Sep 22, 2026	11-50	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 22, 2026
5	Cascadia Consulting Group	Partial evidence	Seattle, WA, United StatesHQ checked Sep 22, 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 22, 2026
6	The Miller Hull Partnership, LLP	Partial evidence	Seattle, WA, United StatesHQ checked Sep 22, 2026	51-200	104 contacts →
	Partial evidence “The Miller Hull Partnership is an architecture and planning firm rooted in environmentally-responsible designs that create a regenerative and inclusive future.” Source: RevenueBase Database · checked Sep 22, 2026
7	Weber Thompson	Partial evidence	Seattle, WA, United StatesHQ checked Sep 22, 2026	51-200	62 contacts →
	Partial evidence “Weber Thompson is an award-winning, majority women-owned design firm based in Seattle that offers full-service architecture, interior design, and landscape architecture.” Source: RevenueBase Database · checked Sep 22, 2026
8	Collinswoerman	Partial evidence	Seattle, WA, United StatesHQ checked Sep 22, 2026	51-200	61 contacts →
	Partial evidence “We believe that great design drives extraordinary value.” Source: RevenueBase Database · checked Sep 22, 2026
9	Floyd Snider	Indirect evidence	Seattle, WA, United StatesHQ checked Sep 22, 2026	11-50	48 contacts →
	Indirect evidence “Floyd\|Snider is a multi-disciplinary environmental consulting firm providing engineering, strategic project management, and scientific expertise to achieve balanced solutions to…” Source: RevenueBase Database · checked Sep 22, 2026
10	SMR Architects	Indirect evidence	Seattle, WA, United StatesHQ checked Sep 22, 2026	11-50	43 contacts →
	Indirect evidence “SMR Architects is a full-service architecture firm established in Seattle in 1977 as Stickney & Murphy Architects.” Source: RevenueBase Database · checked Sep 22, 2026
11	Board & Vellum	Partial evidence	Seattle, WA, United StatesHQ checked Sep 22, 2026	11-50	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 22, 2026
12	HBB Landscape Architecture	Partial evidence	Seattle, WA, United StatesHQ checked Sep 22, 2026	11-50	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 22, 2026
13	Ecotope, INC	Strong evidence	Seattle, WA, United StatesHQ checked Sep 22, 2026	11-50	30 contacts →
	Strong evidence “Ecotope has provided sustainable building design consulting and engineering services in the Pacific Northwest for over 40 years.” Source: RevenueBase Database · checked Sep 22, 2026
14	MIG SVR	Partial evidence	Seattle, WA, United StatesHQ checked Sep 22, 2026	201-500	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 22, 2026
15	ARC Architects	Partial evidence	Seattle, WA, United StatesHQ checked Sep 22, 2026	11-50	27 contacts →
	Partial evidence “ARC Architects works closely with its clients to design projects that meet their needs and inspire their organizations.” Source: RevenueBase Database · checked Sep 22, 2026
16	Weinstein A U	Indirect evidence	Seattle, WA, United StatesHQ checked Sep 22, 2026	11-50	26 contacts →
	Indirect evidence “At Weinstein AU, we look for ways to make our complex world a more balanced, inspirational, and productive place in which to live, work, and participate in civic life.” Source: RevenueBase Database · checked Sep 22, 2026
17	TCA Architecture Planning Design	Partial evidence	Seattle, WA, United StatesHQ checked Sep 22, 2026	11-50	25 contacts →
	Partial evidence “TCA represents a 60+ year evolution of experience providing personalized design services for a wide range of challenging and notable projects.” Source: RevenueBase Database · checked Sep 22, 2026
18	Runberg Architecture Group	Partial evidence	Seattle, WA, United StatesHQ checked Sep 22, 2026	11-50	25 contacts →
	Partial evidence “Since our founding in 1998, Runberg Architecture Group has earned a name for thoughtful design that balances the unique social, economic and environmental interests of each…” Source: RevenueBase Database · checked Sep 22, 2026
19	Jackson Main Architecture, P.S	Partial evidence	Seattle, WA, United StatesHQ checked Sep 22, 2026	11-50	24 contacts →
	Partial evidence “Jackson \| Main Architecture is a full-service architecture and planning firm designing what’s next in the built environment.” Source: RevenueBase Database · checked Sep 22, 2026
20	4ea Building Science	Partial evidence	Seattle, WA, United StatesHQ checked Sep 22, 2026	11-50	22 contacts →
	Partial evidence “4EA Building Science is a full-service design consultancy that specializes in the design, construction, and rehabilitation of building enclosures.” Source: RevenueBase Database · checked Sep 22, 2026
21	Delta E Consulting	Strong evidence	Seattle, WA, United StatesHQ checked Sep 22, 2026	11-50	22 contacts →
	Strong evidence “At Delta E, we specialize in a diverse range of consulting services, including Sustainability, Carbon consulting, Energy services, and design expertise in Mechanical, Electrical…” Source: RevenueBase Database · checked Sep 22, 2026
22	O'brien360	Partial evidence	Seattle, WA, United StatesHQ checked Sep 22, 2026	11-50	21 contacts →
	Partial evidence “O'Brien360 is a nationally recognized leader in the sustainable building community.” Source: RevenueBase Database · checked Sep 22, 2026
23	Johnson Braund, INC	Partial evidence	Seattle, WA, United StatesHQ checked Sep 22, 2026	11-50	21 contacts →
	Partial evidence “Johnson Braund is a full-service architecture firm founded in 1977 that has been designing projects across the nation.” Source: RevenueBase Database · checked Sep 22, 2026
24	Shed Architecture & Design	Indirect evidence	Seattle, WA, United StatesHQ checked Sep 22, 2026	11-50	16 contacts →
	Indirect evidence “SHED engages architecture as a practical art.” Source: RevenueBase Database · checked Sep 22, 2026
25	Cast Architecture	Partial evidence	Seattle, WA, United StatesHQ checked Sep 22, 2026	11-50	16 contacts →
	Partial evidence “CAST architecture is a Seattle-based firm with extensive experience designing contemporary spaces throughout the Northwest.” Source: RevenueBase Database · checked Sep 22, 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: sustainable 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 sustainable design firms.
Partial evidence: Its own public description names part of sustainable design firms, so it works in or next to the category without describing itself that way.
Indirect evidence: The description shown does not name sustainable 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 121 sustainable design firms based in Seattle, United States

See the full list, filter by size, metro and specialty, and get verified emails and direct dials for all 1,704 reachable decision-makers.

Free signup · no credit card

View the full list →

Sustainable design firms based in Seattle, United States at a glance

As of Sep 22, 2026

59.2%Verified-email coverage

23.8Average contacts per company

1-10Median size (employees)

266.1%Largest-city concentration · New York

Sep 22, 2026Page data refreshed

Companies by employee count

1-10

11-50

51-200

201-500

501-1,000

1,001-5,000

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 121 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 sustainable 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 “sustainable 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 sustainable 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 sustainable 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, 1,704 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 22, 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.

Sustainable design firms by metro in the United States

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 sustainable 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 sustainable design firms are there based in Seattle, United States?

RevenueBase identified 121 sustainable 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?

Parametrix, headquartered in Seattle, tops this list with the largest team on record.

Which city has the most sustainable design firms?

New York leads with 322 headquartered companies, followed by Los Angeles (146) and Seattle (121).

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 1,704 verified decision-maker contacts tracked across these 121 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 22, 2026.

Ready to reach these companies? Verified emails and direct dials for all 121 sustainable design firms based in Seattle, United States. Start with a free account, no credit card.

Download this list →

Related lists

Sustainable design firms by geography

Browse the directory

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.