Principal Designer Services

Building confidence. Designing for safety.

Bringing safety, compliance and clear coordination together from the start.

The Building Safety Act and subsequent changes to the Building Regulations have introduced clearer responsibilities for clients, designers and contractors in England, alongside more rigorous approval processes for Higher-Risk Buildings. Together with the existing CDM Regulations, this framework places greater emphasis on competence, coordinated design and evidence of compliance.

BTP provides Principal Designer services under both the Building Regulations and CDM Regulations, helping clients navigate these responsibilities with confidence.

Our six RIBA-accredited Principal Designers include specialists qualified to work on Higher-Risk Buildings. We bring design, technical and safety expertise together to identify risks early, coordinate compliance and maintain clear evidence throughout the project.

From managing pre-construction health and safety to guiding project teams through the Building Safety Regulator’s Gateway process, we provide practical support that keeps safety and compliance central to project delivery.

Both our Principal Designer roles can be delivered individually or together as one coordinated service.

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Director
Leanne Beirne

BA(Hons), M.Arch, RIBA, ARB
Director
Leanne Beirne

BA(Hons), M.Arch, RIBA, ARB

I’m an architect with specialist experience in housing and heritage projects, with a particular focus on fire safety and cladding remediation. I qualified in 2015 and joined BTP in 2017, following roles in Singapore and Sweden working on public buildings, BIM management and accessible design.

I am qualified as a Certified European Passive House Designer, a RIBA accredited Conservation Architect, and became one of the first Architects to be listed on the RIBA Principal Designer Register for Higher Risk Buildings (HRBs).

Outside work, I like to keep fit with running, hiking, weightlifting, skiing and rock climbing. Travel and adventure are a big part of my life, from completing the Inca Trail and climbing Kilimanjaro to running my first (and probably only) marathon on the Great Wall of China.
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Director
Simon Dennis

BSc, BArch(Hons), RIBA

Director
Simon Dennis

BSc, BArch(Hons), RIBA

I joined BTP in 2015, bringing a portfolio of Judicial and Custodial refurbishment projects to the practice, which I still continue to develop, including several conservation projects. More recently, I have also developed my role as a Principal Designer on both HRB & Non-HRB projects, particularly for custodial and education projects.

Since Graduating from Dundee University in 1996 I have gained considerable experience as an architect through completing a broad range of project types and sizes; from domestic projects for private clients to multi-million pound construction programmes for Government bodies and International commercial organisations throughout the UK. My predominant skills are in job running, detailed design, conservation projects and project management.

Outside of the office I am an enthusiastic hill-walker and climber and enjoy the outdoors, from gentle country strolls, ticking off Wainwrights and Munros, or summitting international peaks. I am also a keen traveller with a collection of passport stamps from Iceland to Antarctica.
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Director
Elliot Denby

BA(Hons), M.Arch, RIBA, ARB

Director
Elliot Denby

BA(Hons), M.Arch, RIBA, ARB

I qualified as an Architect in 2017 joining BTP the same year, was promoted to Associate in 2019 and became a Director in 2023.

Since joining BTP, I’ve led projects from concept through to completion, ranging from large-scale housing developments to refurbishment and high-rise fire remediation. These include an award-winning 34-home affordable housing scheme in Wythenshawe and successful Gateway 2 applications for Hatton Gardens in Liverpool and The Blake in Southampton. I’ve also built a strong relationship with a major national contractor, delivering high-rise remediation and refurbishment projects across England and Scotland.

As an accredited Building Regulations Principal Designer, I have a particular interest in building safety and compliance. My strengths lie in job running, detailed design and project management, helping projects progress smoothly and meet the required standards.

Outside of work I enjoy spending time with my family, travelling where possible to explore different cultures and running recently completing the Great North Run 2025 and London Marathon in 2026.