OverviewA leading multi-disciplinary building services consultancy delivering innovative, sustainable engineering solutions across a wide range of sectors including healthcare, education, commercial, and mission-critical environments. With a strong project footprint across the UK and Ireland, they offer a collaborative, BIM-integrated design environment and a culture that supports personal and professional development. As the business continues to expand, they are seeking a highly experienced Principal Mechanical Design Engineer to lead the mechanical discipline across major projects.What you'll be doingIn this key role, you'll lead the design and delivery of complex mechanical building services packages for both new-build and refurbishment projects. You'll work across the full project lifecycle - from concept to commissioning - and play a central role in both project execution and team development. This is a senior leadership role, combining technical delivery with mentoring, project coordination, client engagement, and BIM integration.ResponsibilitiesLead mechanical design from concept to detailed design, tender, and construction stages.Develop technically sound, regulation-compliant designs across a range of mechanical systems:HVAC (ventilation, heating, and cooling)Domestic hot and cold-water servicesLTHW/CHW systemsRenewable/low carbon technologies (e.g. ASHP, GSHP, CHP)Steam and compressed air (as required)Building Management Systems (BMS) and control strategiesOversee and mentor engineers and design teams, ensuring technical quality, delivery standards, and programme alignment.Prepare and review detailed mechanical calculations (duct/piping sizing, heat loss/gain, pressure drops, equipment selection).Coordinate mechanical designs with architectural, structural, sustainability, and other MEP disciplines.Attend and lead technical meetings, design reviews, workshops, and client presentations.Ensure compliance with UK and Irish building regulations, energy performance standards, and best practices.Support the integration of BIM Level 2 and ISO 19650 standards across all project stages.Technical & Regulatory KnowledgeStrong understanding of:UK Building Regulations (Part L), BRUKL assessmentsCIBSE Guides A, B, etc.BSRIA guides and Soft LandingsBREEAM, LEED, and Net Zero Carbon principlesIrish Technical Guidance Documents (TGD Part L)Tools & Digital SkillsHevacomp (load and sizing calculations)IES VE (thermal modelling, DSM, Part L compliance)MagiCAD for AutoCAD/Revit (system design)Autodesk Revit MEP (3D coordination, BIM)AutoCAD (2D schematics)Microsoft Excel (engineering calculations/schedules)Familiarity with BMS integration platforms (e.g. Trend, Siemens)Degree in Mechanical or Building Services Engineering (BEng/BSc minimum; MEng desirable).Chartered Engineer (CEng) with CIBSE or IMechE - or actively pursuing.8-10+ years of UK-based experience in mechanical building services design, with demonstrable team and project leadership.Experience delivering major schemes with £10M+ M&E value.Strong command of UK BIM workflows and coordination protocols (ISO 19650).Excellent communication and client engagement skills.Desirable ExperienceExperience in whole-life carbon and decarbonisation strategies (e.g., TM65).Cross-border experience with both UK and Irish design standards.Sector-specific knowledge (e.g. HTM for healthcare, DfE guidelines for education, or data centre design).Experience preparing bid documentation, fee proposals, and project delivery plans.Rewards & BenefitsJoin a collaborative, forward-thinking consultancy where your technical leadership and input will shape the success of major national projects. Expect the opportunity to work with high-performing teams and influence the delivery of low-energy, sustainable designs.Competitive salary and packageFlexible/hybrid workingCPD support and route to further leadershipMeaningful project work across UK and IrelandInclusive, growth-focused company culture #J-18808-Ljbffr