Martyn’s Law 2025: U.K. Venue Security & Compliance for the Built Environment

The Terrorism (Protection of Premises) Act 2025, better known as Martyn’s Law, introduces a new legal duty for U.K. venues and publicly accessible locations. For those operating in the built environment, from sports and public assembly venues to cultural and community institutions, retail destinations and transport hubs, the implications are wide-ranging. 

Raising the Standard for Protective Design

Until now, there has been no specific legal requirement for venues to adopt counterterrorism measures. Martyn’s Law changes this by mandating that those responsible for public spaces plan for and reduce vulnerability to terrorist threats, with obligations scaled by capacity: 

• Standard Duty (200–799 people): Requires staff procedures for evacuation, lockdown, invacuation and communications.
• Enhanced Duty (800+ people): Requires additional risk assessments, physical measures such as CCTV, access control and perimeter security, plus the appointment of a designated senior individual accountable for compliance.

For the sports and public assembly sectors in particular, protective design strategies will now be an integral part of project planning, operations and life cycle management. 

Bridging Design, Operations & Compliance

Martyn’s Law reinforces the need to combine design, engineering and operational planning. For venues, the challenge is achieving compliance without compromising guest experience, aesthetics or commercial viability. Priority actions include: 

• Comprehensive risk assessment: Evaluating vulnerabilities in both new builds and existing assets.
• Operational readiness: Embedding training and response procedures with the same rigour as fire safety.
• Engineering solutions: Integrating access control, blast resistance, secure perimeters and surveillance into the design of stadia, arenas and transport hubs.
• Life cycle resilience: Ensuring compliance is documented and adaptable as facilities evolve. 

Preparedness & Organisational Culture

The Act places as much emphasis on preparedness as on physical measures. It requires venues to ensure that staff are regularly trained and aware of their roles in an emergency, that security plans are clearly documented and kept up to date, and that risk assessments are reviewed and adapted as venues change in use, capacity or threat profile. Taken together, these measures represent a cultural shift: security is no longer an afterthought but must become embedded in everyday governance, planning and operations.

Implications for Public Venues

Protective design is no longer optional. Martyn’s Law establishes a tiered framework of duties based on venue size. Venues with capacities of 200 to 799 people must ensure that staff are trained and prepared to carry out evacuation, invacuation, lockdown and communication procedures. Larger venues – those with 800 or more people – face additional obligations: they must conduct detailed risk assessments, implement protective measures such as surveillance, access control and perimeter security, and appoint a designated senior individual who will be accountable for compliance. Across both tiers, the principle of “reasonably practicable” applies, requiring venues to put in place proportionate, risk-based measures aligned to their specific circumstances. 

The aim is to design spaces that are resilient, adaptable and capable of protecting the public while remaining open and functional. For a detailed analysis of Martyn’s Law, including legal, operational and financial implications, as well as practical steps for compliance, download our comprehensive report: 

Martyn's Law: Overview of Business Impact and Compliance of the Terrorism Act 2025

Need help navigating security design measures in response to Martyn’s Law?

Authored By  

David Weston, U.K. Security Compliance Lead

London, United Kingdom

David Weston is an internationally experienced senior intelligence and security consultant with a proven record of delivering high-risk projects across the private sector, the Ministry of Defence, government and partner agencies. At Thornton Tomasetti, he leads security compliance across Europe and Australia and advises clients on operational security planning and strategy.