TRETHOWAN - Key Persons


Claire Miller

Job Titles:
  • Associate
Claire joined Trethowan's heritage team in 2015, coming from an architectural background with a particular interest in historic buildings. She brings extensive academic experience to her role, utilising research and analytical skills to provide advice and assessments on a range of project types and scales. Her approach to heritage is to advocate for significant buildings and to negotiate positive outcomes for all stakeholders by balancing contemporary needs and historic sensitivity. As associate, Claire supports the strategic direction of the practice, and the growth and development of the heritage team as industry leaders. This role allows Claire to foster positive relationships with clients, authorities, and consultants in a collaborative approach to managing heritage places.

Emily Bartlett

Job Titles:
  • Photographer

Iain Nicol

Job Titles:
  • Director
Starting with Trethowan in 2007, Iain Nicol has helped to shape the direction of the firm and its architectural response to buildings within a heritage context. As the architectural practice director, he has fostered the growth and development of the passionate and talented architects and designers that form the architectural team at Trethowan. He has a contemporary approach to architecture, with a heritage sensitivity.

Isabella Chow


Mark Stephenson

Job Titles:
  • Director
  • Practice Director
Mark is the heritage practice director with a passion for heritage places and well-considered contextual design that enhances and supports these important places. He brings extensive experience and practical knowledge to Trethowan and each project. He values the importance of understanding the significance of a heritage place, and uses this understanding to collaborate with owners and experts to deliver a project that not only provides for current needs, but adds to the history of the heritage place.

Priyan Perera

Job Titles:
  • Associate
Priyan joined Trethowan in 2014 and has since led a variety of high-end residential, commercial & heritage-related projects; actively liaising with clients, consultants & contractors through all stages of the architectural process. He has been integral in Trethowan's adoption of new systems and technologies all aimed at expanding the capabilities and efficiency of our office. Outside of Architecture Priyan maintains a passion for graphic, furniture, and industrial design, which inform a holistic and multidisciplinary approach to all of his architectural projects, regardless of type and scale. As associate, Priyan continues his research into growing and improving office standards and internal procedures. Leading internal working groups created to collaborate, share knowledge, and assist in the development and upskilling of his colleagues.