Principal Mechanical Design Engineer

Company: 12 Recruitment Ltd
Apply for the Principal Mechanical Design Engineer
Location: London
Job Description:

Principal Mechanical MEP Design Engineer

Location: LondonSalary: 85,000Progression: Associate / Director–level opportunities

Lead mechanical design on challenging, bespoke projects within a growing London consultancy, with the opportunity to develop a team, influence project delivery and progress into senior leadership.

We are working with a London–based building services consultancy looking to appoint a Principal Mechanical Design Engineer. This is an opportunity for an experienced engineer to take technical ownership of complex projects, support junior team members and play a key role in the continued development of the business.

The Role

  • Lead mechanical building services design across a range of complex, one–off projects.

  • Take responsibility for projects from concept through to detailed design and delivery.

  • Provide technical leadership and oversee design quality.

  • Manage, mentor and develop engineers within the team.

  • Coordinate mechanical designs with electrical, structural and architectural disciplines.

  • Attend client meetings and develop strong working relationships.

  • Support project delivery, technical reviews and design coordination.

  • Contribute to the development of engineering standards and working practices.

  • Help drive the growth and technical capability of the consultancy.

Requirements

  • Extensive experience in mechanical building services design.

  • Strong knowledge of HVAC, ventilation, heating and cooling systems.

  • Experience leading projects and taking ownership of technical delivery.

  • Ability to manage, mentor and support other engineers.

  • Strong understanding of relevant building services standards and regulations.

  • Confident working with clients and multidisciplinary project teams.

  • Experience delivering technically challenging or bespoke projects.

  • Degree–qualified in Mechanical Engineering or Building Services Engineering, or equivalent experience.

  • Chartered status, or working towards chartership, would be advantageous.

The Opportunity

  • Salary of 85,000.

  • A clear progression route into Associate and potentially Director–level leadership.

  • The opportunity to lead and develop a small team.

  • Exposure to challenging, bespoke building services projects.

  • A senior role offering genuine influence over technical delivery and business development.

Please note: Candidates must already have the right to work in the UK. Visa sponsorship cannot be offered.

#J-18808-Ljbffr…

Posted: October 17th, 2026