Castria offers an integrated architecture and engineering service through a truly collaborative design process and our creative business culture.


Castria offers an integrated architecture and engineering service through a truly collaborative design process and our creative business culture.  Our talented team of architects, engineers, surveyors and designers apply their technical expertise and imaginative problem-solving skills to a wide range of sectors and scale of projects.

For all projects we aim to provide an excellent service and value for our clients. We want to contribute to great placemaking, to be instrumental in reducing impact on the natural environment and in sustaining the historic environment.

The Royal Military Academy Sandhurst | Castria Design


We are architects, engineers, and innovators working
on some of the UK's most prestigious projects.


We are professionals in managing and delivering design, leveraging on knowledge from a variety of disciplines to customise a project particularly to the demands of our clients.

We deliver the aspirations of our clients from feasibility study to concept design, from detailed design to interior architecture. We do this by listening carefully and researching the project brief, prioritising the client’s objectives, providing inspiration and understanding the budget.

The team always work closely with the client to evolve, and deliver design excellence throughout planning, procurement, and the construction phases of a project.

We offer a full architectural design, Principal Designer, Interior Architecture and contract administration services in sectors spanning hospitality, civic, cultural, residential, defence, education, commercial, and industrial.

Our engineering team is highly experienced across a wide range of sectors including commercial, residential, civic, industrial, and education but with specific specialist expertise in the defence sector and in marine structural, environmental, and civil engineering. We provide flood risk services as part of our core offer.

We strive for cost effective solutions for all our projects, but also those which best meet the project objectives. We work with the wider team to achieve excellent outcomes for interventions in the more sensitive historic and natural environments to maintain their values and to minimise impact. Where innovation is needed, we provide expertise and guidance on appropriate strategies and the management of risk.

The engineering team can be augmented to cover Building Services, specialist survey and access activities for a reassuringly comprehensive and integrated design team offer.

Castria is expert in managing change in the historic environment, with specialists across the disciplines in strategic heritage management, conservation practice and conservation engineering. We are knowledgeable in methods of conservation and repair, adept at the creative and sustainable adaptation of heritage properties and in introducing new build structures and interventions sensitively within the historic environment.

The work we do for visual inspections, Quadrennials and Quinquennials is supplemented with the latest technology supporting our conservation work using 3D point cloud survey data, the use of drones and ground penetrating radar.

Masterplanning is fundamental to sustainable development, and we place great significance as a team on designs which involve the community in shaping the built environment. We are experienced in integrating urban design principles in all types of development, landscape design-led approaches, experiential design, low carbon strategies, community consultation and more creative engagement practice. 

Caerphilly Castle | Medieval fortification in Caerphilly in South Wales | Castria Design

"The company is focussed on the principle that successful projects are best produced by a closely integrated design team working together in a truly co-operative environment"

David Hollingsworth – Technical Director


Castria is an RIBA Chartered Practice with Chartered Architects and AABC registered Conservation Architects and a RICS Building Surveyor. We employ engineers chartered with the Institution of Civil Engineers and with the Institution of Structural Engineers.

All our staff undergo a programme of continued professional development. We are committed to sustaining the training of specialists in heritage conservation and engineering.

Working with schools, further and higher education on work experience and project specific activities is vital to what we do. We offer structured training placements across the design disciplines and have recently completed the inaugural RIBA mentoring scheme with Architecture undergraduates at Falmouth University.

Castria is an Equal Opportunities Employer.

Commander of the Heights Regeneration | Public Use | Castria Design

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We know from experience that the most authentic and successful projects are those that reflect the shared identity of the community.

Social, economic and environmental sustainability is integral to our design processes and underpin our culture We operate an Environmental Policy and Environmental Management System. Environmental management is integral to both our business practice and the design services we provide to our clients.

Team members have designed or delivered projects to BREEAM and DREAM as well as LEED and GSAS standards. We can carry out CEEQUAL Environmental Assessments.

We are signatories to Architects Declare and are committed to the mitigation of the impacts of Climate Change.

In accordance with our Ethical Business and Anti-slavery Policy, we will treat people respectfully and sustain ethical corporate values in all the sectors in which we operate.

We do business with clients and suppliers whose standards align and are consistent with ours and are committed to the community and the environment to safeguard consistent levels of transparency in our approach.

As a long established multi-disciplinary consultancy, we have been early adopters of technologies which support collaborative working and the use of BIM in effective design coordination and project delivery.

Increasingly, in addition to coordination and data management, we are using the technology to support strong design communication at the early stages of the design to help clients and stakeholders especially in our heritage work and through planning stages to visualise projects and to assess their impact.

We are ISO 9001:2015 Quality Management accredited with the BSI.

We are CHAS, JOSCA and Constructionline Gold registered

Castria is the new trading name of PDP Green Consulting Ltd.

The new brand and website launched in June 2021.

Command of the Heights Greenspace Regeneration Project | Castria Design


Our practice is organised into multidisciplinary teams focused on producing intelligent,
innovative design solutions across an array of sectors.