Principal MEP Mechanical Engineer Outside IR35 Hybrid Role Purpose The Principal MEP Mechanical Engineer will lead the mechanical engineering delivery of residential and commercial construction projects from pre-construction through commissioning and handover. The role acts as the senior mechanical technical authority, ensuring systems are compliant, coordinated, cost-effective, and buildable while supporting programme, quality, and safety objectives. Key Responsibilities Technical & Delivery Leadership Lead mechanical engineering delivery across multiple residential and commercial projects. Take ownership of mechanical design development and construction-stage design responsibility on D&B projects. Review, challenge, and manage consultant designs to ensure buildability, value, and programme certainty. Ensure compliance with UK legislation and standards, including: Building Regulations (Part L, Part F, Part O, Part G) CIBSE Guides and Technical Memoranda BS EN standards and relevant British Standards BSRIA commissioning guides Heat Network (Metering and Billing) Regulations where applicable Provide technical leadership across HVAC, domestic water services, drainage, above-ground soil and waste, and specialist mechanical systems.Pre-Construction & Design Management Provide mechanical input into bids, tenders, and pre-construction activities. Review Employer's Requirements, specifications, and performance criteria...