A leading multidisciplinary building services consultancy is seeking a Senior Sustainability Engineer to join its growing team of environmental design experts. This is a high-impact role for an experienced professional looking to drive sustainability strategy, shape building performance outcomes, and contribute to a wide range of innovative, low-carbon developments across the UK and internationally. Key Responsibilities: Lead sustainability design input across all project stages, from concept through to construction. Develop and implement sustainability strategies for buildings and masterplans, aligned with client goals and regulations. Manage and deliver assessments under key frameworks such as BREEAM, LEED, WELL, HQM, and Net Zero Carbon Pathways. Perform building performance modelling (e.g., energy, carbon, daylight, thermal comfort) and advise on improvements. Ensure compliance with national and local energy policy, including Part L, TM52/59, and London Plan energy strategies. Produce clear and concise reports, client presentations, and technical documentation. Mentor junior engineers and contribute to internal knowledge sharing. Stay updated on industry trends, technologies, and legislative changes. Liaise with clients, architects, and contractors to ensure integration of sustainability principles. Skills and Qualifications: Degree in Mechanical Engineering, Environmental Design, Building Services, or a related sustainability-focused discipline. Minimum 5 years of relevant experience in sustainability or building performance engineering. Accredited BREEAM Assessor, WELL AP, or LEED AP (preferred). Strong knowledge of UK and international sustainability regulations and certifications. Experience with software tools such as IES VE, DesignBuilder, SAP/SBEM, One Click LCA, or IES Apache. Understanding of life cycle assessment (LCA), embodied carbon, and circular economy principles. Excellent written and verbal communication skills. Ability to manage multiple projects and deadlines simultaneously. Benefits: Competitive salary based on experience 25 days holiday + bank holidays Flexible and hybrid working options Company pension scheme Support for professional development and chartership Annual training budget and internal CPD program Regular team socials and industry events Cycle to Work scheme Employee wellness program and mental health support Opportunity to work on net-zero, award-winning projects Skills: Senior Sustainability Engineer