horncastle:thomas Limited is a renowned RIBA Chartered Architects practise established in 2011 on the Isle of Man by experienced architects Karen Horncastle and Martyn Thomas. With a combined experience of over 20 years in the local area, Karen has a deep understanding of the architectural landscape, while Martyn has honed his skills in leading architectural firms across North West England before returning to his roots.

Our practise is dedicated to creating exceptional designs for a diverse range of projects, including listed and registered buildings, as well as new constructions in conservation areas. We firmly believe in the importance of good modern design, taking into account the context, environment, and local constraints. By integrating innovative design technology with a respect for historical architecture, horncastle:thomas strives to achieve excellence in every project, no matter the scale.