Principal Mechanical Engineer in Maidenhead

Sweco is looking for a talented and motivated Principal Mechanical Building Services Engineer to join our Maidenhead/London office to lead the delivery of sustainable, high‑performing building services solutions and to act as a trusted advisor to our clients. You will play a key role in shaping projects and people across our business, working within Sweco’s four cornerstones: Client Focus, Best People, Internal Efficiency and Decentralised Organisation.

Our highly regarded mechanical, electrical and public health experts, sustainability teams and certification specialists collaborate with clients across the UK to transform vision into reality – with a unique blend of creativity and commercial pragmatism at the heart of everything we do.

What does the role involve?

• Lead mechanical design on complex, multi‑disciplinary projects from concept to delivery.
• Act as a principal point of contact for clients, understanding their drivers and translating them into clear design solutions.
• Facilitate early‑stage engagement, develop briefs and lead technical presentations, workshops and design reviews.
• Drive value through low‑carbon, energy‑efficient and whole‑life design thinking.

Best People

• Provide technical leadership and direction for project teams, setting high standards for design quality and innovation.
• Mentor and develop engineers and technicians, supporting professional progression and chartership.
• Contribute to technical excellence through internal forums, knowledge sharing and guidance documents.

Internal Efficiency

• Plan and manage mechanical work packages, ensuring delivery to agreed time, cost and quality.
• Champion effective use of digital tools (e.g. BIM, analysis software, collaboration platforms).
• Apply and improve standard processes, specifications and QA procedures to reduce rework and increase consistency.

Decentralised Organisation

• Take ownership of key technical decisions and support local teams to deliver projects for their markets.
• Collaborate with colleagues across offices and disciplines, contributing to market, client and capability development.
• Feed insights from projects and clients back into our wider business strategy.

Qualifications And Experience

• Degree in Mechanical Engineering or related discipline.
• Chartered Engineer (CEng) or equivalent professional status.
• Significant experience in mechanical building services design across multiple sectors and project stages.
• Proven track record of leading multi‑disciplinary project teams and managing client relationships.
• Strong knowledge of UK Building Regulations, CIBSE guidance and relevant standards.
• Demonstrable experience in low‑carbon and sustainable building services design.
• Excellent communication skills and commercial awareness.

Knowledge And Skills

• Strong technical expertise in building services systems (e.g. heating, cooling, ventilation, electrical public health) and their integration with fabric and other disciplines.
• Thorough understanding of relevant regulations, standards and guidance (e.g. UK Building Regulations, CIBSE, BS/EN/ISO).
• Demonstrable experience in low‑carbon, energy‑efficient and sustainable design, including familiarity with relevant assessment methods where applicable.
• Competence with relevant design, analysis and BIM tools and an understanding of their role in integrated design.
• Strong analytical and problem‑solving skills, able to balance technical rigour with practical, buildable solutions.
• Excellent written and verbal communication skills, including the ability to explain complex issues to non‑technical stakeholders.

Behaviours

• Proactive, accountable and organised, able to manage multiple assignments and competing priorities.
• Collaborative, supportive and inclusive, with a commitment to developing others.
• Client‑focused with sound commercial awareness and a focus on value.
• Aligned with Sweco’s values and committed to delivering a sustainable, people‑centred built environment.

Employee Benefits

• Flexible and hybrid working (Flexworks Policy)
• Competitive pension contribution
• Life Assurance
• Private Medical Insurance
• Company car or car allowance
• Discretionary Annual Bonus Scheme
• Payment of two relevant professional subscriptions
• 25 days holiday plus bank holidays (with the option to purchase up to 5 additional days per year)
• Cycle2Work Scheme
• Employee Assistance Programme (wellbeing, mental health, financial and work advice)
• Employee discounts via Sweco Benefit Select (Faircare)
• Salary Sacrifice Electric Vehicle Scheme
• We plant a tree for all new starters!

Here at Sweco we positively encourage applications from suitably qualified and eligible candidates regardless of sex, race, disability, age, sexual orientation, gender reassignment, religion or belief, marital status, pregnancy or maternity/paternity.