Job Title\: Principal Engineer - Mechanical Engineering (Site & Facilities) Location: Barrow-in-Furness - Hybrid, 3 days per week onsite with ad hoc factory visits We offer a range of hybrid and flexible working arrangements - please speak to your recruiter about the options for this particular role Salary: £47,241 depending on experience Who we are: Join BAE Systems and you’ll be part of something bigger. As a valued member of our global colleague network, you’ll bring your unique skills and perspectives to help pioneer progress and protect what matters most. You’ll be trusted to play your part in delivering the advanced, technology-led defence, aerospace and security solutions of tomorrow, shaping a safer future, for all of us. From the depths of the ocean, to the far reaches of space, there’s no limit to where a career at BAE Systems could take you. Job Description: As a member of the Site Specialist Engineering (SSE) team. Your role is responsible for leading the definition of mechanical design requirements for HVAC (Heating, Ventilation & Air Conditioning) and/or LEV (Local exhaust Ventilation) site developments, utilising knowledge and experience as a key stakeholder in collaboration with end users and project teams. You will also be reviewing mechanical design proposals and specifications for both new facility developments and the refurbishment of existing installations to ensure compliance with current legislation, regulations and site standards. Core duties: You will provide guidance and technical recommendations to the wider business for HVAC/LEV services You will conduct visual assessments of on-site equipment and provide technical guidance You will coordinate with stakeholders such as Engineering Authorities, on-site Occupational Hygienists and DSEAR engineers to assess operations on site and ensure LEV systems are safe, legal and compliant, in accordance with relevant regulations You will prepare technical reports and documentation to support new HVAC and LEV installations on site You will develop and maintain site engineering standards for HVAC and LEV systems as required You will support and lead junior engineers Essential Skills: You will bring a proven background in the design, installation, commissioning or maintenance of HVAC and/or LEV systems You will have an understanding of the principals of ventilation and cooling/heating design You will be experienced in developing or interpreting design proposals and technical documentation for HVAC and/or LEV systems You will be familiar with relevant HVAC and/or LEV standards and legislation You will be degree level education, preferably in Building Services Engineering or a closely related discipline The Site Specialist Engineering (SSE)Team: Joining a multi-disciplinary engineering team comprising Suitably Qualified and Experienced Personnel in Electrical, Mechanical and Civil/Structural disciplines. The SSE set site engineering standards and requirements for equipment/systems/facilities in accordance with legislation and processes, operating as part of the wider Barrow-in-Furness Site and Facilities team. You will provide SME knowledge in a number of disciplines, including HVAC & LEV. We offer relocation support packages across all Submarines roles, subject to meeting eligibility criteria. Why BAE Systems? Here you’ll build a career with purpose and limitless possibilities. With lifelong learning and meaningful work, this is a place where you can grow your career with confidence and be empowered to be your best. You’ll be recognised for your contribution and enjoy rewards tailored to what’s most important to you and your family, support for your financial and personal wellbeing, as well as a balanced lifestyle. In an environment embracing sustainable ways of working and with a strong sense of shared purpose, our supportive culture is a place you can feel you belong and proud of the difference you make. A place where everyone can thrive: We’re committed to building an inclusive workplace where everyone feels valued and supported. We know that a diversity of backgrounds, perspectives and experiences strengthens our teams and is vital to the work we do. We welcome applications from all suitably qualified people, who are BAE Systems employees and have been in their current role for 12 months or longer. Please be aware that many roles at BAE Systems are subject to both security and export control restrictions. These restrictions mean that factors such as your nationality, any nationalities you may have previously held, and your place of birth can restrict the roles you are eligible to perform within the organisation. All applicants must as a minimum achieve Baseline Personnel Security Standard. Many roles also require higher levels of National Security Vetting where applicants must typically have 5 to 10 years of continuous residency in the UK depending on the vetting level required for the role, to allow for meaningful security vetting checks. Closing Date\: 22nd April 2026 We reserve the right to close this vacancy early if we receive sufficient applications for the role. Therefore, if you are interested, please submit your application as early as possible. LI-GV1 LI-Hybrid