Donald Insall Associates

For over 65 years, Donald Insall Associates has shaped how the world views heritage. Sir Donald Insall’s pioneering approach redefined conservation as a dynamic process of managing change. His belief that the historic environment must continuously evolve remains central to our work today.

Heritage is not just to be protected but understood, cared for, and shaped for the future. We take a considered approach, balancing tradition and transformation to help the historic environment remain purposeful and resilient. Sustainability is fundamental to this process—guiding how we conserve, adapt, and reimagine heritage to meet the needs of tomorrow. Every intervention is informed by deep expertise, commercial awareness, and a commitment to meaningful change—ensuring the past continues to enrich contemporary life.

As an employee-owned practice with national reach, we offer expertise in conservation, heritage consultancy, new design in historic settings, and townscape advice. We see the full picture—materials, history, evolving policy—bringing insight and precision to every project. Our collaborative approach bridges architecture, design, and heritage consultancy—uniting deep knowledge and a shared vision to create solutions that serve clients, partners, and communities.

We think critically, act boldly, and find new ways to ensure the historic environment continues to thrive. Through research, engagement, and advocacy, we shape best practices and set the standard for what heritage can be.

By leading conversations and driving progress in the field, we ensure that heritage is not static, but a living, evolving legacy.

At DIA, we guide change with intelligence, integrity, and innovation—ensuring heritage continues to serve, inspire, and endure.