An opportunity has arisen for an experienced Mechanical Design Engineer to support the delivery of a major infrastructure upgrade programme within a complex operational environment. This Mechanical Design Engineer role is ideal for someone with strong HVAC and public health design experience who enjoys delivering technically challenging projects while working closely with construction and delivery teams. The successful Mechanical Design Engineer will join an established project team responsible for delivering critical infrastructure upgrades, with a particular focus on ventilation, smoke extract, drainage and water services systems. The Role As a Mechanical Design Engineer, you'll be involved in: Delivering mechanical building services designs across major infrastructure projects Designing HVAC, ventilation and smoke extract systems Producing foul drainage and potable water system designs Undertaking mechanical calculations, specifications and technical reports Supporting projects through detailed design and construction stages Coordinating with multidisciplinary engineering and project delivery teams Attending site meetings and technical reviews Providing construction support and responding to technical queries Assisting with design changes and project modifications throughout delivery This role requires both strong design capability and practical construction awareness, with opportunities to support multiple workstreams as projects progress. What They're Looking For Experience as a Mechanical Design Engineer within building services environments Strong HVAC and ventilation design capability Experience designing smoke extract systems Knowledge of foul drainage and potable water systems Good understanding of mechanical design calculations and system sizing Strong communication and stakeholder management skills Ability to support projects through both design and construction phases Experience within infrastructure, transportation, aviation, commercial or other complex project environments would be advantageous. Why Apply? Outside IR35 contract opportunity Major infrastructure upgrade programme Long-term 6-month contract with extension potential Exposure to technically challenging building services projects Opportunity to combine design and construction-stage responsibilities Established engineering and project delivery team Immediate interviews available. If you're a Mechanical Design Engineer with strong HVAC, ventilation and public health design experience looking for your next Outside IR35 contract, apply now to be considered.