Living history

Securing a future for the oldest building on the Parliamentary estate

Places for the community

From a derelict site to a thriving café

A contemporary extension

Stitching in new with the old

Reducing in-use energy

Installing solar panels atop a Grade I-listed Cathedral

Guiding change in heritage sites

A practical guide to managing change within a scheduled ancient monument

We are conservation architects and heritage consultants.

For over 65 years we have pioneered a creative and pragmatic approach to managing change within the historic environment. Our clients include custodians of the most significant historic buildings in the UK, commercial developers, preservation trusts applying for National Lottery Heritage Fund support, owners of country estates as well as local authorities. Proudly BCorp-certified.

Our portfolio

Creative conservation of a 1000-year-old cathedral

Chester Cathedral

From vacant offices to family home

Private House, Camden

Extending a Medieval home

Private House, Staffordshire

An accessible visitor shop and events space

The Undercroft, Hampton Court Palace

Townscape advice for a Modernist landmark

Space House

Services

Whether it is architectural or heritage consultancy services you are after, we offer practical and creative input that unlocks opportunities within your site.

Latest news

A tea house for all: The Camellia House at Wentworth Woodhouse wins 2025 Europa Nostra Awards

Planning application for London Liverpool Street transformation now validated by City of London

What clients tell us

" Creating an architectural project that embraces the need to be commercially viable, accessible, and compliant but is also sensitive to the age and architectural integrity of our site is a very difficult balancing act. The DIA team did their very best to try to balance these requirements and although compromises have had to be made, the end result is that we are more accessible, safer, compliant, repaired and with the potential to attract many revenue-bearing visitors to our Heritage site – one of the best and most important medieval sites in Britain – perhaps Europe. It is not an easy undertaking in such a complex and demanding architectural site for an architectural team and the DIA team performed this task with grace, compassion and integrity. "

Dr Heidi L Meyer, Master, Lord Leycester Hospital

Lord Leycester Hospital

Get in touch

We have studios in London, Bath, Birmingham, Chester, Conwy, Manchester, Oxford and York.