The purpose of the Head of Transitional Security role is to lead the design, implementation, and transition of robust security measures for data centre construction projects across the UK and Europe. In addition to supporting Arks commitment to Health and Safety standards, the position requires the post holder to act as the Subject Matter Expert (SME), converging inputs from diverse internal and external stakeholders, including construction and design teams, customer experience, technical and electronic services, operational security, and specialist security consultancy firms, to ensure seamless integration of protective measures throughout the project lifecycle. Reporting directly to the Director of Security, the role involves managing the entire security project lifecycle, from initial design consultation (RIBA Stage 0 onwards) to final commissioning* and handover to the Security Operations Team, while ensuring strict compliance with HMG, NPSA (National Protective Security Authority), and European security standards (where applicable). Collaborating closely with the Head of Electronic Security to ensure all ESS products meet security standards and undergo thorough compliance assessment.