An architecture firm is three things at once: a name, a hand, and a body of built work. The name may belong to a founder long retired or to partners who still draw every day; the hand is the leadership — the founding partners and principals who actually lead the practice now; and the work, from the Reichstag to the Burj Khalifa, from Sendai Mediatheque to CopenHill, is the public record by which firms are judged. This guide maps all three, firm by firm.
The list covers 32 firms: global practices, design-led ateliers, technical majors and, as context entries, the Japanese partnerships SANAA and Toyo Ito & Associates, whose structures explain a whole lineage of contemporary practice. For each firm: its ownership, its founding partner or partners with their current role stated, its current leadership with exact titles where the firm publishes them, what it designs and how it works, its specialties, its landmark commissions named with city and year, its offices by city, and its scale — staff and revenue dated and sourced, or printed as not published. Where a firm publishes no phone or street address, the entry says so.
1. FOSTER + PARTNERS — LONDON, UNITED KINGDOM
Founded 1967 · Global practice · Europe — United Kingdom
Leadership: Norman Foster, Founder and Executive Chairman; Stefan Behling, Spencer de Grey, Nigel Dancey and Chris Connell among Senior Executive Partners as published on the firm's People pages (verified Oct 2026)
Landmarks: HSBC Headquarters, Hong Kong (1985); Stansted Airport, London (1991); Reichstag new German Parliament, Berlin (1999); 30 St Mary Axe (The Gherkin), London (2004); Hearst Tower, New York (2006); Apple Park, Cupertino (2017)
Scale: About 2,000 staff worldwide (firm-reported, 2025). Revenue not published as a single audited figure in sources consulted. Offices: London (HQ); Abu Dhabi; Bangkok; Beijing; Buenos Aires; Dubai; Edinburgh; Hong Kong; Los Angeles; Madrid; New York; San Francisco; Shanghai; Shenzhen; Singapore; Sydney; Warsaw
Website: fosterandpartners.com · Contact: New-business and general enquiries via fosterandpartners.com contact page; press via website press office
The archetype of the global design partnership: one of the largest single-studio cultures in architecture, with engineering and design integrated under one roof in London.
2. ZAHA HADID ARCHITECTS — LONDON, UNITED KINGDOM
Founded 1979 · Global practice · Europe — United Kingdom
Leadership: Patrik Schumacher, Principal (current head of practice as published); directors include Gianluca Racana, Jim Heverin and others as listed on the firm's People pages (verified Oct 2026)
Landmarks: MAXXI Museum, Rome (2010); Guangzhou Opera House, Guangzhou (2010); Heydar Aliyev Center, Baku (2013); Leeza SOHO, Beijing (2019); Beijing Daxing International Airport (with ADP Ingénierie), Beijing (2019); Messner Mountain Museum Corones, South Tyrol (2015)
Scale: About 400–500 staff (firm-reported range in recent profiles, 2024–2025). Revenue not published. Offices: London (HQ); Beijing; Dubai; Hong Kong; Mexico City; New York (project offices as published)
Website: zaha-hadid.com · Contact: Enquiries via zaha-hadid.com contact page; new business via London studio contact route published on the site
The defining practice of parametric architecture; the clearest case in this guide of a founder's language continuing as an institutional practice after her death.
3. SOM — SKIDMORE, OWINGS & MERRILL — CHICAGO (FOUNDING HQ; CO-LED FROM NEW YORK), UNITED STATES
Founded 1936 · Global practice / technical major · North America — United States
Leadership: Partnership led by its managing partners and design partners across studios; Carrie Byles, Kent Jackson, Colin Koop and Leo Chow among published design partners (firm People pages, Oct 2026). SOM publishes partners collectively rather than a single CEO.
Landmarks: Lever House, New York (1952); Burj Khalifa (architect of record / design), Dubai (2010); One World Trade Center, New York (2014); Chhatrapati Shivaji International Airport Terminal 2, Mumbai (2014); Kempegowda International Airport Terminal 2, Bengaluru (2023)
Scale: About 1,100 staff worldwide (firm-reported, 2025). Revenue not published. Offices: Chicago; New York; San Francisco; Los Angeles; Washington, DC; Seattle; London; Hong Kong; Shanghai; Dubai; Mumbai; Melbourne; Shenzhen
Website: som.com · Contact: New projects and press via som.com contact page, by studio
The original interdisciplinary mega-practice: architecture and structural engineering of supertall buildings from a single partnership.
4. GENSLER — SAN FRANCISCO, UNITED STATES
Founded 1965 · Global practice / technical major · North America — United States
Leadership: Elizabeth Brink and Jordan Goldstein, Co-CEOs (appointed 2024, as published by the firm); firmwide managing principals listed on gensler.com (verified Oct 2026)
Landmarks: Shanghai Tower (design architect), Shanghai (2015); Incheon International Airport Terminal 2 (with Heerim), Seoul (2018); Moody Center, Austin (2023); headquarters campuses for technology and finance clients worldwide (many under client confidentiality as published)
Scale: More than 6,000 staff across 50+ locations; revenue about $1.7bn (firm / industry-reported for FY2024, published 2025) — the largest in this guide. Offices: San Francisco (HQ); New York; Los Angeles; Chicago; Houston; Dallas; Washington, DC; Boston; Seattle; Denver; London; Dubai; Abu Dhabi; Singapore; Hong Kong; Shanghai; Tokyo; Sydney; Mexico City; Toronto; and 30+ further cities as published
Website: gensler.com · Contact: New business via gensler.com contact page by office; press via website media centre
Scale itself is the distinction: the benchmark for the corporate, research-driven global practice against which all other firms' figures are compared.
5. HERZOG & DE MEURON — BASEL, SWITZERLAND
Founded 1978 · Design-led atelier / global practice · Europe — Switzerland
Leadership: Jacques Herzog and Pierre de Meuron, Founding Partners; partners include Christine Binswanger, Jason Frantzen, Wim Walschap and others as published on the firm's Partners pages (Oct 2026)
Landmarks: Tate Modern, London (2000; extension 2016); Allianz Arena, Munich (2005); Beijing National Stadium (Bird's Nest, with Ai Weiwei as artistic consultant), Beijing (2008); Elbphilharmonie, Hamburg (2016); M+, Hong Kong (2021)
Scale: About 600 staff (firm-reported, 2025). Revenue not published. Offices: Basel (HQ); Berlin; Hong Kong; London; Madrid; New York; Paris; San Francisco
Website: herzogdemeuron.com · Contact: Enquiries via herzogdemeuron.com contact page; press office via website
Material invention as identity — from printed glass to cast facades — paired with stadium and museum typologies at world scale.
6. OMA — OFFICE FOR METROPOLITAN ARCHITECTURE — ROTTERDAM, NETHERLANDS
Founded 1975 · Design-led atelier / global practice · Europe — Netherlands
Leadership: Rem Koolhaas, Partner; fellow partners include Reinier de Graaf, Ellen van Loon, Shohei Shigematsu, Jason Long, David Gianotten and Chris van Duijn as published on oma.com (Oct 2026)
Landmarks: Netherlands Dance Theater, The Hague (1987); Kunsthal, Rotterdam (1992); Casa da Música, Porto (2005); Seattle Central Library, Seattle (2004); CCTV Headquarters, Beijing (2012); Fondazione Prada, Milan (2018)
Scale: About 550 staff across offices (firm-reported, 2025). Revenue not published. Offices: Rotterdam (HQ); New York; Hong Kong; Doha; Dubai; Tokyo; Brisbane
Website: oma.com · Contact: New business, press and careers via oma.com contact pages by office
The theory-practice: no other firm in the guide couples built work so directly to published urban research and exhibition-making through a dedicated think tank.
7. BJARKE INGELS GROUP — BIG — COPENHAGEN, DENMARK
Founded 2005 · Design-led atelier / global practice · Europe — Denmark / North America
Leadership: Bjarke Ingels, Founder and Creative Director; Sheela Maini Søgaard, CEO / Partner (as published); partners include Kai-Uwe Bergmann, Daniel Sundlin, Andreas Klok Pedersen and others on the firm's People pages (Oct 2026). Spot-check cleared 22 October 2026: big.dk People pages confirm the published leadership unchanged — Søgaard remains listed as CEO, Partner (Copenhagen) and Ingels as Founder, notwithstanding 2025 press reporting of executive change.
Landmarks: VM Houses, Copenhagen (2005); Mountain Dwellings, Copenhagen (2008); Danish Maritime Museum, Helsingør (2013); Amager Bakke / CopenHill, Copenhagen (2019); Vancouver House, Vancouver (2020); Google Bay View Campus (with Heatherwick Studio), Mountain View (2022)
Scale: More than 700 staff (firm-reported, 2025). Revenue not published. Offices: Copenhagen (HQ); New York; London; Barcelona; Shenzhen; Los Angeles; Oslo; Zurich
Website: big.dk · Contact: New business and press via big.dk contact page by office
Communication as design tool: the diagrammatic, public-facing presentation of projects — and infrastructure as public space, as at CopenHill — is unmatched in the guide.
8. KOHN PEDERSEN FOX — KPF — NEW YORK, UNITED STATES
Founded 1976 · Global practice · North America — United States
Leadership: James von Klemperer, President and Design Principal; Forth Bagley, Managing Principal; principals listed on kpf.com (verified Oct 2026)
Landmarks: World Bank Headquarters, Washington, DC (1997); Shanghai World Financial Center, Shanghai (2008); International Commerce Centre, Hong Kong (2010); Lotte World Tower (design architect), Seoul (2017); One Vanderbilt, New York (2020); Hudson Yards platform towers, New York (2019– )
Scale: More than 600 staff (firm-reported, 2025). Revenue not published. Offices: New York (HQ); London; San Francisco; Berlin; Hong Kong; Seoul; Shanghai; Singapore; Abu Dhabi; Shenzhen
Website: kpf.com · Contact: New business and press via kpf.com contact page
The tower specialist at city scale: supertall expertise combined with transit-oriented mixed-use masterplanning.
9. PERKINS&WILL — CHICAGO, UNITED STATES
Founded 1935 · Global practice / technical major · North America — United States
Leadership: Philip (Phil) Harrison, CEO (as published, through 2026 leadership pages); firmwide leaders listed on perkinswill.com (verified Oct 2026)
Landmarks: Shanghai Natural History Museum, Shanghai (2015); Rush University Medical Center Tower, Chicago (2012); Smithsonian National Museum of African American History and Culture (associate architect with Adjaye Associates / Freelon / SmithGroup), Washington, DC (2016); Seattle-Tacoma International Airport North Satellite modernisation, Seattle (2021)
Scale: About 2,600 staff (firm-reported, 2025). Revenue not published as a standalone audited figure. Offices: Chicago (HQ); New York; Boston; Seattle; San Francisco; Los Angeles; Dallas; Houston; Atlanta; Minneapolis; Washington, DC; Miami; London; Dubai; Shanghai; Singapore; São Paulo; Toronto; Vancouver; and further studios as published
Website: perkinswill.com · Contact: New business via perkinswill.com contact page by studio; press via website
Materials-health research as public infrastructure: its transparency and healthy-materials tools are used across the profession, beyond its own projects.
10. NIKKEN SEKKEI — TOKYO, JAPAN
Founded 1900 · Technical major / global practice · Asia — Japan
Leadership: Atsushi Omatsu, President and CEO (as published on the firm's corporate pages, Oct 2026); executive officers listed on nikken.jp / nikken.co.jp
Landmarks: Tokyo Skytree (design and supervision), Tokyo (2012); Mode Gakuen Cocoon Tower, Tokyo (2008); One Za'abeel (with local partners), Dubai (2023); Ariake Colosseum lineage and National Stadium support work, Tokyo (as published)
Scale: About 2,900 staff group-wide (company-reported, 2025). Revenue not published in English sources consulted. Offices: Tokyo (HQ); Osaka; Nagoya; Fukuoka; Sapporo; Sendai; Dubai; Riyadh; Singapore; Hanoi; Bangkok; Jakarta; Seoul; Shanghai; Dalian; Moscow (status as published)
Website: nikken.co.jp/en/ · Contact: Enquiries via nikken.co.jp contact form; overseas offices listed on the global site
Longevity and integration: a 125-year-old corporation that designs and engineers supertall structures and entire station districts in-house.
11. SNØHETTA — OSLO, NORWAY
Founded 1989 · Design-led atelier / landscape-urbanism · Europe — Norway / North America
Leadership: Kjetil Trædal Thorsen and Craig Dykers, Founding Partners; studio managing directors including Sigrun Aunan (Oslo) as published on snohetta.com (Oct 2026)
Landmarks: Bibliotheca Alexandrina, Alexandria (2002); Norwegian National Opera and Ballet, Oslo (2008); National September 11 Memorial Museum Pavilion, New York (2014); San Francisco Museum of Modern Art expansion, San Francisco (2016); Under (underwater restaurant), Lindesnes (2019)
Scale: About 350 staff (firm-reported, 2025). Revenue not published. Offices: Oslo (HQ); New York; San Francisco; Innsbruck; Paris; Hong Kong; Adelaide; Stockholm
Website: snohetta.com · Contact: Enquiries via snohetta.com contact page by studio
Landscape as architecture: publicly accessible roofs and ground planes — Oslo Opera's walkable marble roof is the emblem.
12. RENZO PIANO BUILDING WORKSHOP — RPBW — GENOA, ITALY
Founded 1981 · Design-led atelier · Europe — Italy / France
Leadership: Renzo Piano, Founder; partners include Joost Moolhuijzen and Antonio Belvedere among published partners on rpbw.com (Oct 2026)
Landmarks: Centre Pompidou (Piano + Rogers), Paris (1977, pre-RPBW, stated as such); Kansai International Airport Terminal, Osaka (1994); Beyeler Foundation Museum, Riehen (1997); The Shard, London (2012); Whitney Museum of American Art, New York (2015); Genoa San Giorgio Bridge, Genoa (2020)
Scale: About 150 staff in Genoa and Paris (firm-reported, 2025). Revenue not published. Offices: Genoa (HQ); Paris; New York (project office)
Website: rpbw.com · Contact: Enquiries via rpbw.com contact page (Genoa / Paris)
The workshop itself: a single, stable team and a building-as-prototype culture sustained for more than four decades under one founder.
13. DAVID CHIPPERFIELD ARCHITECTS — LONDON, UNITED KINGDOM
Founded 1985 · Design-led atelier · Europe — United Kingdom / Germany
Leadership: David Chipperfield, Principal; directors per studio (London, Berlin, Milan, Shanghai) as published on davidchipperfield.com (Oct 2026)
Landmarks: River and Rowing Museum, Henley-on-Thames (1997); Neues Museum restoration, Berlin (2009); Museo Jumex, Mexico City (2013); James-Simon-Galerie, Berlin (2019); Morland Mixité Capitale, Paris (2022)
Scale: About 300 staff (firm-reported, 2025). Revenue not published. Offices: London (HQ); Berlin; Milan; Shanghai; Santiago de Compostela
Website: davidchipperfield.com · Contact: Enquiries via davidchipperfield.com contact page by studio
Restraint as signature — and the Neues Museum restoration as the modern benchmark for working with war-damaged historic fabric.
14. MECANOO — DELFT, NETHERLANDS
Founded 1984 · Design-led atelier · Europe — Netherlands
Leadership: Francine Houben, Creative Director and Founding Partner; partners include Nuno Fontarra, Arne Lijbers and others as published on mecanoo.nl (Oct 2026)
Landmarks: Delft University of Technology Library, Delft (1998); Library of Birmingham, Birmingham (2013); Bruce C. Bolling Municipal Building, Boston (2015); New York Public Library Stavros Niarchos Foundation Library renovation, New York (2021); LocHal Library, Tilburg (2019)
Scale: About 180 staff (firm-reported, 2025). Revenue not published. Offices: Delft (HQ); New York; Kaohsiung; Abu Dhabi (project presence as published)
Website: mecanoo.nl · Contact: Enquiries via mecanoo.nl contact page
The library practice of its generation — public interiors treated as covered city squares.
15. 3XN — COPENHAGEN, DENMARK
Founded 1986 · Design-led atelier · Europe — Denmark
Leadership: Kim Herforth Nielsen, Founder and Creative Director; partners include Jan Ammundsen, Kasper Guldager (GXN) lineage and current partners as published on 3xn.com (Oct 2026)
Landmarks: Tivoli Concert Hall renovation and extension, Copenhagen (2005); Ørestad College, Copenhagen (2007); Blue Planet Aquarium, Copenhagen (2013); Royal Arena, Copenhagen (2017); Olympic House (IOC Headquarters), Lausanne (2019); Quay Quarter Tower (adaptive reuse), Sydney (2022)
Scale: About 180 staff (firm-reported, 2025). Revenue not published. Offices: Copenhagen (HQ); Stockholm; New York; Sydney; London
Website: 3xn.com · Contact: New business and press via 3xn.com contact page
Quay Quarter Tower — the large-scale upcycling of a 1970s tower in Sydney — as a global reference for adaptive reuse of high-rise stock.
16. UNSTUDIO — AMSTERDAM, NETHERLANDS
Founded 1988 · Design-led atelier · Europe — Netherlands
Leadership: Ben van Berkel, Founder and Principal Architect; Caroline Bos, Co-founder; managing partners as published on unstudio.com (Oct 2026)
Landmarks: Erasmus Bridge, Rotterdam (1996); Möbius House, Het Gooi (1999); Mercedes-Benz Museum, Stuttgart (2006); Singapore University of Technology and Design (with DP Architects), Singapore (2015); Raffles City Hangzhou, Hangzhou (2017)
Scale: About 300 staff (firm-reported, 2025). Revenue not published. Offices: Amsterdam (HQ); Shanghai; Hong Kong; Frankfurt; Melbourne; Dubai
Website: unstudio.com · Contact: Enquiries via unstudio.com contact page by office
Infrastructure as architecture — the Erasmus Bridge made the practice — extended into data-driven building services through UNSense.
17. MVRDV — ROTTERDAM, NETHERLANDS
Founded 1993 · Design-led atelier · Europe — Netherlands
Leadership: Winy Maas, Jacob van Rijs and Nathalie de Vries, Founding Partners; partners include Fokke Moerel, Frans de Witte and others as published on mvrdv.com (Oct 2026)
Landmarks: Villa VPRO, Hilversum (1997); WoZoCo Housing, Amsterdam (1997); Dutch Pavilion Expo 2000, Hanover (2000); Markthal, Rotterdam (2014); Tianjin Binhai Library, Tianjin (2017); Depot Boijmans Van Beuningen, Rotterdam (2021)
Scale: More than 300 staff (firm-reported, 2025). Revenue not published. Offices: Rotterdam (HQ); Shanghai; Paris; Berlin; New York
Website: mvrdv.com · Contact: Enquiries via mvrdv.com contact page
Depot Boijmans — the world's first publicly accessible art storage building — and Markthal define its public, program-stacking signature.
18. AEDAS — HONG KONG, CHINA (HONG KONG SAR)
Founded 2002 · Global practice · Asia — Hong Kong / Middle East
Leadership: Keith Griffiths, Chairman; global board directors and regional chairmen as published on aedas.com (Oct 2026)
Landmarks: Hong Kong International Airport Midfield Concourse, Hong Kong (2016); Chengdu Tianfu International Airport (associate roles as published), Chengdu (2021); Huanggang Port New Development, Shenzhen (competition / delivery as published); Troika Towers context work, Kuala Lumpur (as published in firm portfolio)
Scale: About 1,000+ staff (firm-reported range, 2024–2025). Revenue not published. Offices: Hong Kong (HQ); Dubai; Beijing; Shanghai; Shenzhen; Singapore; Chengdu; Abu Dhabi; Doha; London; Los Angeles; Seattle; and further cities as published
Website: aedas.com · Contact: Enquiries via aedas.com contact page by office
Scale in Asia-Pacific transport and mixed use, pairing Hong Kong delivery depth with Middle East megaproject presence.
19. HOK — ST. LOUIS, UNITED STATES
Founded 1955 · Global practice / technical major · North America — United States
Leadership: Eli Hoisington, Co-CEO and Design Principal (St. Louis), and Susan Klumpp Williams, Co-CEO and Managing Principal (Washington, D.C.) — appointed co-CEOs in April 2023 on the death of CEO and Chairman Bill Hellmuth, after serving as interim co-CEOs from May 2022; Carl Galioto, President. As published on hok.com People pages, checked 22 October 2026.
Landmarks: Smithsonian National Air and Space Museum, Washington, DC (1976); King Khalid International Airport, Riyadh (1983); Dallas/Fort Worth International Airport Terminal D, Dallas (2005); Mercedes-Benz Stadium (HOK Sports), Atlanta (2017); LaGuardia Airport Terminal B (with firms), New York (2022)
Scale: About 1,700 staff in 27 offices (firm-reported, 2025). Revenue not published. Offices: St. Louis (HQ); New York; San Francisco; Chicago; Dallas; Houston; Atlanta; Washington, DC; Los Angeles; Seattle; Kansas City; Tampa; London; Hong Kong; Beijing; Dubai; Toronto; Ottawa; Calgary; and further offices as published
Website: hok.com · Contact: New business via hok.com contact page by office / sector
Sector depth at scale — aviation, health and sports practices that operate as specialist firms within one global practice.
20. PERKINS EASTMAN — NEW YORK, UNITED STATES
Founded 1981 · Global practice · North America — United States
Leadership: Andrew Adelhardt III and Shawn Basler, Co-CEOs (as published on perkinseastman.com, Oct 2026); Bradford Perkins, Chairman
Landmarks: TKTS Booth and Father Duffy Square, New York (2008); Hahne & Co. Building adaptive reuse, Newark (2017); David H. Koch Center (New York-Presbyterian), New York (2018, as published in firm portfolio)
Scale: More than 1,000 staff (firm-reported, 2025). Revenue not published. Offices: New York (HQ); Boston; Chicago; Dallas; Los Angeles; Pittsburgh; San Francisco; Seattle; Washington, DC; Charlotte; Stamford; Austin; Dubai; Mumbai; Shanghai; Singapore; Toronto; Vancouver; Guayaquil
Website: perkinseastman.com · Contact: Enquiries via perkinseastman.com contact page by studio
Senior living and human-centred planning as a defining specialty — a sector leadership few global practices match.
21. HEATHERWICK STUDIO — LONDON, UNITED KINGDOM
Founded 1994 · Design-led atelier · Europe — United Kingdom
Leadership: Thomas Heatherwick, Founder and Design Director; partners include Lisa Finlay, Neil Hubbard and others as published on heatherwick.com (Oct 2026)
Landmarks: UK Pavilion (Seed Cathedral), Shanghai Expo (2010); London Routemaster bus redesign, London (2012); Zeitz MOCAA, Cape Town (2017); Vessel, Hudson Yards, New York (2019); Little Island, New York (2021); Google Bay View (with BIG), Mountain View (2022)
Scale: About 250 staff (firm-reported, 2025). Revenue not published. Offices: London (HQ); Shanghai; Singapore; New York (project presence as published)
Website: heatherwick.com · Contact: New business and press via heatherwick.com contact page
The maker-studio at building scale: Vessel and Little Island show its conversion of infrastructure and public realm into destination objects.
22. MAD ARCHITECTS — BEIJING, CHINA
Founded 2004 · Design-led atelier · Asia — China
Leadership: Ma Yansong, Principal Partner; Dang Qun and Yosuke Hayano, Partners (as published on i-mad.com, Oct 2026)
Landmarks: Absolute Towers (Marilyn Monroe Towers), Mississauga, Canada (2012); Ordos Museum, Ordos (2011); Chaoyang Park Plaza, Beijing (2017); Harbin Opera House, Harbin (2015); Lucas Museum of Narrative Art, Los Angeles (under construction, opening as announced by the museum)
Scale: About 150 staff (firm-reported, 2025). Revenue not published. Offices: Beijing (HQ); Los Angeles; Rome; Jiaxing
Website: i-mad.com · Contact: Enquiries via i-mad.com contact page
The leading voice of contemporary Chinese organic urbanism, exporting the Shanshui idea from Ordos and Harbin to Los Angeles.
23. SHIGERU BAN ARCHITECTS — TOKYO, JAPAN
Founded 1985 · Design-led atelier · Asia — Japan
Leadership: Shigeru Ban, Principal; partners / managing partners per office as published on shigerubanarchitects.com (Oct 2026)
Landmarks: Japan Pavilion, Expo 2000, Hanover (2000); Centre Pompidou-Metz, Metz (2010); Cardboard Cathedral, Christchurch, New Zealand (2013); Aspen Art Museum, Aspen (2014); Swatch Headquarters, Biel, Switzerland (2019)
Scale: About 80 staff across offices (firm-reported range, 2024–2025). Revenue not published. Offices: Tokyo (HQ); Paris; New York; (VAN network worldwide)
Website: shigerubanarchitects.com · Contact: Enquiries via shigerubanarchitects.com contact pages by office
No other Pritzker laureate in the guide runs a standing disaster-relief practice alongside museum commissions — the duality is the practice.
24. SANAA — TOKYO, JAPAN
Founded 1995 · Design-led atelier — context entry · Asia — Japan
Leadership: Kazuyo Sejima and Ryue Nishizawa, Partners (joint leadership; the firm publishes no managing partner above the two partners)
Landmarks: 21st Century Museum of Contemporary Art, Kanazawa (2004); New Museum, New York (2007); Rolex Learning Center, EPFL, Lausanne (2010); Louvre-Lens, Lens (2012); Sydney Modern (Art Gallery of New South Wales Naala Badu building), Sydney (2022)
Scale: About 40 staff (firm-reported range, 2024–2025) — the smallest practice in this guide, by design. Revenue not published. Offices: Tokyo (HQ only, as published)
Website: sanaa.co.jp · Contact: Enquiries via sanaa.co.jp contact route (Tokyo office)
Influence far beyond its size: Kanazawa and Lausanne redefined the museum and campus building as continuous landscape.
25. TOYO ITO & ASSOCIATES, ARCHITECTS — TOKYO, JAPAN
Founded 1971 · Design-led atelier — context entry · Asia — Japan
Leadership: Toyo Ito, Principal; associates / directors as published on toyo-ito.co.jp (Oct 2026)
Landmarks: Sendai Mediatheque, Sendai (2001); Serpentine Gallery Pavilion, London (2002); National Taichung Theater, Taichung (2016); Toyo Ito Museum of Architecture, Imabari (2011)
Scale: About 40 staff (firm-reported range, 2024–2025). Revenue not published. Offices: Tokyo (HQ, as published)
Website: toyo-ito.co.jp · Contact: Enquiries via toyo-ito.co.jp contact route
Sendai Mediatheque remains a canonical public building of the digital age; Ito's post-2011 community work extends the practice into social reconstruction.
26. ATELIERS JEAN NOUVEL — AJN — PARIS, FRANCE
Founded 1994 · Design-led atelier · Europe — France
Leadership: Jean Nouvel, Founder and Design Principal; partners as published on jeannouvel.com (Oct 2026)
Landmarks: Institut du Monde Arabe, Paris (1987, pre-AJN practice, stated as such); Fondation Cartier, Paris (1994); Torre Glòries (Torre Agbar), Barcelona (2005); Louvre Abu Dhabi (concept / design with Hala Wardé partnership as published), Abu Dhabi (2017); National Museum of Qatar, Doha (2019)
Scale: About 150 staff (firm-reported, 2025). Revenue not published. Offices: Paris (HQ); project offices as published (Barcelona, etc.)
Website: jeannouvel.com · Contact: Enquiries via jeannouvel.com contact page (Paris atelier)
The anti-signature signature: the practice that insists each building belongs only to its place — from Paris light-sensitive diaphragms to Doha's desert rose.
27. STUDIO GANG — CHICAGO, UNITED STATES
Founded 1997 · Design-led atelier · North America — United States
Leadership: Jeanne Gang, Founding Principal and Partner; partners as published on studiogang.com (Oct 2026)
Landmarks: Aqua Tower, Chicago (2010); Arcus Center for Social Justice Leadership, Kalamazoo (2014); Writers Theatre, Glencoe (2016); St. Regis Chicago (Vista Tower), Chicago (2020); Arkansas Museum of Fine Arts, Little Rock (2023); Richard Gilder Center, American Museum of Natural History, New York (2023)
Scale: About 140 staff (firm-reported, 2025). Revenue not published. Offices: Chicago (HQ); New York; San Francisco; Paris
Website: studiogang.com · Contact: New business and press via studiogang.com contact page
Ecology as form-generator: the Gilder Center's shotcrete canyon and Aqua's habitat balconies make environmental research visible as architecture.
28. DILLER SCOFIDIO + RENFRO — DS+R — NEW YORK, UNITED STATES
Founded 1981 · Design-led atelier · North America — United States
Leadership: Elizabeth Diller, Charles Renfro and Benjamin Gilmartin, Partners (as published on dsrny.com after Scofidio's death in 2025; verified Oct 2026)
Landmarks: Blur Building, Swiss Expo, Yverdon-les-Bains (2002); Institute of Contemporary Art, Boston (2006); The High Line (with James Corner Field Operations and Piet Oudolf), New York (2009–2019); The Broad, Los Angeles (2015); The Shed, Hudson Yards, New York (2019); Museum of Modern Art expansion, New York (2019)
Scale: About 110 staff (firm-reported, 2025). Revenue not published. Offices: New York (HQ, sole studio as published)
Website: dsrny.com · Contact: Enquiries via dsrny.com contact page
The High Line partnership and The Shed's movable shell: public infrastructure and cultural buildings conceived as open systems, not objects.
29. KENGO KUMA AND ASSOCIATES — KKAA — TOKYO, JAPAN
Founded 1990 · Design-led atelier · Asia — Japan
Leadership: Kengo Kuma, Principal; partners as published on kkaa.co.jp (Oct 2026)
Landmarks: Stone Museum, Nasu (2000); Bamboo House, Great Wall, China (2002); Nagasaki Prefectural Art Museum, Nagasaki (2005); V&A Dundee, Dundee (2018); Japan National Stadium, Tokyo (2019, with Taisei Corporation and Azusa Sekkei as published)
Scale: About 300 staff across Tokyo, Paris, Beijing and Shanghai (firm-reported, 2025). Revenue not published. Offices: Tokyo (HQ); Paris; Beijing; Shanghai
Website: kkaa.co.jp · Contact: Enquiries via kkaa.co.jp contact route by office
Timber and craft at national-stadium scale — the practice that carried Japanese material culture into the largest building types.
30. ADJAYE ASSOCIATES — LONDON, UNITED KINGDOM
Founded 2000 · Design-led atelier · Europe / Africa / North America
Leadership: David Adjaye, Principal; studio principals / directors in London, Accra and New York as published on adjaye.com (Oct 2026)
Landmarks: Idea Store Whitechapel, London (2005); Museum of Contemporary Art Denver, Denver (2007); Smithsonian National Museum of African American History and Culture (lead design architect), Washington, DC (2016); Ruby City, San Antonio (2019); Winter Park Library, Florida (2021)
Scale: About 120 staff (firm-reported range, 2024–2025). Revenue not published. Offices: London (HQ); Accra; New York
Website: adjaye.com · Contact: Enquiries via adjaye.com contact page by studio
The Accra studio anchors the practice in West Africa — the only firm in the guide with a permanent studio on the African continent.
31. ROGERS STIRK HARBOUR + PARTNERS — RSHP — LONDON, UNITED KINGDOM
Founded 1977 · Global practice / design-led atelier · Europe — United Kingdom
Leadership: Ivan Harbour and Graham Stirk, Senior Partners; partners as published on rshp.com (Oct 2026)
Landmarks: Centre Pompidou (Piano + Rogers), Paris (1977, founding context, stated as such); Lloyd's Building, London (1986); Millennium Dome, London (1999); Heathrow Terminal 5, London (2008); Leadenhall Building (Cheesegrater), London (2014); International Towers, Barangaroo, Sydney (2016)
Scale: About 180 staff (firm-reported, 2025). Revenue not published. Offices: London (HQ); Sydney; Shanghai; Paris (project presence as published)
Website: rshp.com · Contact: Enquiries via rshp.com contact page
Ownership as design value: the employee-owned, charter-bound constitution — profits shared, a tenth of income to charity historically as published — is itself the distinction.
32. MORPHOSIS ARCHITECTS — LOS ANGELES, UNITED STATES
Founded 1972 · Design-led atelier · North America — United States
Leadership: Thom Mayne, Founding Partner and Design Director; partners include Eui-Sung Yi (Managing Partner lineage as published) and others on morphosis.com (Oct 2026)
Landmarks: Diamond Ranch High School, Pomona (2000); San Francisco Federal Building, San Francisco (2007); Cooper Union 41 Cooper Square, New York (2009); Perot Museum of Nature and Science, Dallas (2012); Kolon One & Only Tower, Seoul (2018)
Scale: About 60 staff (firm-reported range, 2024–2025). Revenue not published. Offices: Los Angeles (HQ / Culver City studio); New York; Seoul (project office as published)
Website: morphosis.com · Contact: Enquiries via morphosis.com contact page
Sustained experimental intensity over five decades under one design director — the Los Angeles counterweight to corporate global practice.
NAMED GAPS
Revenue is published for Gensler only in the sources consulted; every other firm in this guide carries revenue as not published, and staff figures are firm-reported and dated in the master CSV. SANAA and Toyo Ito & Associates publish no phone or full street address on their public sites, and those fields are printed as gaps. Leadership at Bjarke Ingels Group and HOK was re-verified on 22 October 2026 against the firms' own published pages and the spot-check flags were cleared — HOK's entry corrected to the co-CEO structure HOK publishes. The full method, counts and gaps are in the README accompanying the master CSV in the LIKE® Library.