Principal​/Associate Mechanical Design Engineer

Location: City of London

Job Profile for Principal/Associate Mechanical Design Engineer 48092

A collaborative building services and environmental design consultancy is looking to appoint a Principal or Associate Mechanical Design Engineer to join its London-based team. This is an excellent opportunity for an ambitious engineer to develop their career within a supportive design environment, working alongside experienced professionals on a varied range of innovative and project-led instructions.

The business has an established reputation in zero-carbon building services engineering, environmental design, and digital 3D design/BIM (Revit) expertise, aiming to help create a world where every building is truly zero carbon. With a strong pipeline of work and a collaborative team, this role offers the opportunity to lead exciting projects, develop technical expertise, and contribute to pioneering sustainable construction solutions.

Principal/Associate Mechanical Design Engineer Benefits:

£60,000 - £95,000, depending on experience (covering Principal through Associate levels)
24 days holiday + bank holiday
Comprehensive healthcare cover including dental and eyecare (upon successful completion of probation)
Mental health support and bereavement counselling
Group life insurance cover provided from day one
Contributory company pension scheme
Professional membership subscriptions covered (e.g., CIBSE, IMechE, IET)
Regular continued professional development and support to attain or maintain chartership
Hybrid and flexible working model

Principal/Associate Mechanical Design Engineer Job Overview:

The successful candidate will join an established team of building services and environmental engineering professionals, working across a range of high-profile residential, commercial, and specialist project-based instructions. Depending on seniority, the role will involve acting as Project Lead across multiple projects and, at the Associate level, acting as Team Coordinator and line manager to guide team members, manage resources, and oversee project delivery.

Working closely with directors and senior colleagues, you will lead engineering design at all project stages. The business is keen to empower engineers, providing real project ownership, strong client-facing exposure, and clear pathways for career progression within the leadership structure.

The role will include:

Leading the mechanical engineering design across multiple projects from concept to completion.
Undertaking detailed load calculations, equipment sizing, and environmental/thermal modelling considerations.
Producing design packages, stage reports, 2D/3D BIM coordination specifications, and technical schedules.
Managing project fees, resources, and project profitability.
Acting as the primary client-facing contact and liaising with external design team members, architects, and contractors.
Visiting sites to conduct inspections, ensuring design intent and construction standards are met.
Providing technical engineering leadership internally, delegating tasks, and mentoring junior engineers.
Acting as Line Manager and Team Coordinator, supporting individual welfare, workload allocation, and career development.
Contributing to business development, maintaining architect/client relationships, and staying ahead of sustainability trends.

Principal/Associate Mechanical Design Engineer

Job Requirements:

A degree in Mechanical Engineering, Building Services Engineering, or a related discipline.
Chartered member of either CIBSE, IMechE, or IET.
Proven experience leading project design, managing project finances, and acting as the primary point of contact for external teams.
Strong technical background in mechanical design, building services, and all-electric, low-carbon energy strategies.
Proficiency with 2D AutoCAD and experience using 3D modelling/BIM software such as Revit, alongside familiarity with thermal modelling software such as IES.
Strong knowledge of relevant Building Regulations, CIBSE guidelines, planning policies, British Standards, and CDM responsibilities.
Experience delegating work, supporting junior engineers, and leading internal teams.
Excellent communication, interpersonal, report-writing, and client presentation skills.
A proactive, collaborative approach and a commitment to sustainable, zero-carbon design.

This is an opportunity to join a growing, award-winning consultancy where professional growth is actively supported, with exposure to innovative projects and a clear path for senior leadership

Bennett and Game…