Cat­ja de Haas Archi­tects is a small prac­tice that can design and deliv­er projects of very dif­fer­ent scales. The practice’s main focus is to make life bet­ter for peo­ple in their home and in the community. 

This means build­ing sus­tain­ably by spec­i­fy­ing to Fab­ric First or Pas­siv Haus Stan­dards, whilst thought­ful­ly con­sid­er­ing the impact the build­ing has on its site. We make build­ings that are a plea­sure to use, have lit­tle impact on their envi­ron­ment and can help make exist­ing build­ings more sustainable. 

The prac­tice can man­age all stages of a built project as well as advise on designs for those who want to man­age their own project. We are a col­lab­o­ra­tive prac­tice, whether work­ing direct­ly with a client or bring­ing in exper­tise from areas out­side our knowl­edge base. The Prac­tice is BIM ready.

The prac­tice research­es the home and hous­ing while rais­ing aware­ness of home­less­ness and the refugee cri­sis through the Giant Dolls’house Project.

Please con­tact us if you would like to dis­cuss your project and see what we can offer.

Catja de Haas


Catja, PhD, RIBA, qualified as an architect at Delft University under Professor Herzberger. She also holds an MA in housing and Urbanism from the Architectural Association in London. Prior to setting up on her own she worked for Itsuko Hasegawa in Tokyo where she worked on projects in Japan and Malaysia, and Alsop Architects in London where she worked as a project architect on the Dutch projects. Between 2000 and 2005 she ran a practice, Studio CS, with Sabina Riss. In that time she built the house in France.

The home in miniature was the topic for her PhD by architectural design (supervisors Prof Jonathan Hill and Christine Hawley) which she finished at Bartlett school of Architecture, UCL, in 2013.

The Giant Dolls’ house project is the result of her ongoing research into the use of imagination and miniature to explore the ideas of home and community participation as well as the dolls' house as a medium to bring about change. Catja has exhibited her own work and has presented her work at conferences and universities. She has been a visiting lecturer and crit at various universities.

Sophie Walker

Architectural Assistant

Sophie obtained her MA in Architecture at The Cass, London Metropolitan University and her BA at Oxford Brookes University. She has worked at De Rosee Sa Architects and Matheson Whiteley where she worked on residential and refurbishment projects and a community pavilion in London. She has been working with Catja de Haas on the Giant Dolls’ House Project since the start of 2018 and is also part of a small team compiling a book of essays and work on the Courtier Houses and Soviet social condensers.