Job Description

Senior / Principal Mechanical Design Engineer - Building Services? Location: South Wales | ? Salary: Competitive + Package
? Job Type: Full-time, Permanent
Lead Mechanical Design, Mentor Talent, and Deliver High-Quality Projects
A well-established and highly respected Building Services Contractor in South Wales is seeking a Senior / Principal Mechanical Design Engineer to strengthen their in-house mechanical design team. With a strong pipeline of projects across commercial, education, healthcare, residential, hospitality, and retail sectors, this is an exciting opportunity to take a leadership role with real responsibility.
You'll join a supportive team delivering technically challenging and rewarding projects, from multimillion-pound new builds to complex refurbishments, while having the chance to mentor junior engineers and shape the future of the department.
Key Responsibilities

• Lead mechanical design on projects from concept through to completion
• Attend and chair design and coordination meetings with internal and external teams
• Act as the main point of contact for clients, representing the business professionally
• Ensure all designs comply with UK building regulations, CIBSE guides, and industry standards
• Develop detailed designs using software such as Hevacomp, IES, Revit, and AutoCAD
• Review and oversee drawings, schematics, and specifications
• Mentor and support junior engineers, apprentices, and wider design staff
• Report project progress to the M&E Design Director
• Collaborate with the in-house construction team and multidisciplinary stakeholders

What We're Looking For

• Degree or HNC/HND in Mechanical or Building Services Engineering (or similar)
• Proven experience in mechanical building services design, ideally within a contractor or consultancy
• Strong technical knowledge of HVAC, LTHW/CHW systems, and sustainable design principles
• Competence with design software (Revit, IES, AutoCAD, Hevacomp)
• Ability to lead projects, take ownership of delivery, and work within budgets
• Good commercial awareness and client-facing skills
• Experience in a contracting environment is advantageous, but training can be provided

Why Join?

• Secure, long-term role with a company that invests in its people
• Competitive salary and benefits package, negotiable depending on experience
• Flexible working arrangements where required
• Exposure to a wide range of technically challenging projects
• Real autonomy and the opportunity to influence the growth of the design function
• Supportive environment with clear progression opportunities

If you're a Senior / Principal Mechanical Design Engineer looking to take the next step in your career or work on high-quality projects within a company that values its people, apply now or get in touch for a confidential conversation.

Skills Required