Full-Time

Mechanical Building Service Engineer

Posted on 5/12/2026

ASSYSTEM

ASSYSTEM

5,001-10,000 employees

Engineering services for design, construction, commissioning

No salary listed

Bristol, UK

Hybrid

Hybrid role with 2 days in office and occasional site travel.

Category
Architecture & Civil Engineering (2)
,
Requirements
  • Degree qualified in Mechanical Engineering or related engineering discipline
  • Strong mechanical building services engineering experience within complex building projects
  • Experience delivering designs from concept through commissioning and handover stages
  • Knowledge of UK building regulations, CIBSE standards and engineering procedures
  • Experience managing and coordinating multidisciplinary building design activities
  • Strong understanding of RIBA Plan of Work and Building Services Research and Information Association guidance
  • Excellent communication, stakeholder engagement and collaborative teamworking abilities
  • Ability to work proactively, independently and manage competing project priorities
  • Experience applying quality assurance processes, configuration control and quality management principles
  • Fluent English communication skills
Responsibilities
  • Review mechanical building services execution designs against NNB technical specifications
  • Support development of scopes for early-stage mechanical design packages
  • Coordinate closely with multidisciplinary teams and respective Contract Engineering Leads
  • Challenge supplier proposals where designs diverge from agreed project requirements
  • Maintain focus on health, safety and quality management compliance standards
  • Ensure Lifetime Quality Records documentation remains complete and accurately maintained
  • Support technical resolution of onsite queries, changes and non-conformance reports
  • Manage interfaces with stakeholders, contractors, consultants and wider project delivery teams
  • Support reporting, escalation activities and risk mitigation meetings when required
  • Assist development of final operation and maintenance manuals for completed facilities
Desired Qualifications
  • French language capability would be advantageous

Assystem provides engineering services for complex projects, covering design, construction, supervision, commissioning, and operation, with a strong focus on the nuclear and energy sectors. Its approach combines multidisciplinary engineering teams and project-management capabilities to move projects from initial concept through to operation. The company differentiates itself through a long track record, strategic acquisitions (including Alphatem in 1995 and Mactech Energy Group in 2025) and an early public offering in 2013, which have expanded its capabilities and market reach in the energy and nuclear fields. Its goal is to be a leading, reliable partner for clients by delivering end-to-end engineering services and helping them meet safety, performance, and regulatory requirements across the project lifecycle.

Company Size

5,001-10,000

Company Stage

IPO

Headquarters

Paris, France

Founded

1966

Simplify Jobs

Simplify's Take

What believers are saying

  • Q1 2026 nuclear revenue grew 8% to 81% of €165.8M total with organic 2.2% rise.
  • Acquired L&T Infrastructure Engineering in 2024 boosting India energy market share.
  • Secured UK government frameworks supporting Rolls-Royce SMR's three-reactor contract.

What critics are saying

  • Expleo erodes non-nuclear margins with 15,000 employees and €1.1B scale since 2019 split.
  • Currency drops in pound, rupee, riyal cut international revenue 7.1% in Q1 2026.
  • Framatome and Orano integrate services internally, capturing Assystem's nuclear revenue stream.

What makes ASSYSTEM unique

  • Assystem ranks top 3 worldwide in nuclear engineering since 1966.
  • Provides end-to-end lifecycle services for EPR reactors in Flamanville, Taishan, and Olkiluoto.
  • Partners with Dassault Systèmes on PLM and Virtual Twins for SMR projects.

Help us improve and share your feedback! Did you find this helpful?

Your Connections

People at ASSYSTEM who can refer or advise you

Benefits

Health Insurance

Dental Insurance

Vision Insurance

Unlimited Paid Time Off

Flexible Work Hours

Remote Work Options

Paid Vacation

Paid Holidays

Hybrid Work Options

401(k) Retirement Plan

Wellness Program

Mental Health Support

Gym Membership

Professional Development Budget

Conference Attendance Budget

Stock Options

Company Equity

Phone/Internet Stipend

Home Office Stipend

Relocation Assistance

Childcare Support

Meal Benefits

Parental Leave

Family Planning Benefits

Fertility Treatment Support

Company News

Bdaily
Jan 30th, 2025
Assystem expands UK footprint with takeover

A global nuclear engineering firm has strengthened its UK presence with the acquisition of a specialist construction company. Paris-headquartered Assystem has… | North East | Construction | Engineering | International | Energy | Mergers & Acquisitions | Commercial Partnerships | Manufacturing & Construction |

Assystem
Jan 17th, 2024
Assystem acquires KEOPS Automation, engineering specialist in automated systems and data enhancement

Assystem, an international engineering, digital services and project management company, has acquired 100% of the shares of KEOPS Automation, a French company specializing in the integration of industrial operating platforms and the enhancement of their data (industrial OT and IT, automated systems, supervision systems, BI applied to manufacturing).

Global Construction Review
Jan 5th, 2024
France’s Assystem acquires India’s L&T Infrastructure Engineering - Global Construction Review

France-headquartered engineer and project manager Assystem has acquired India’s L&T Infrastructure Engineering, a subsidiary of the Larsen & Toubro group.

Tech.eu
Feb 11th, 2022
Germany’s SQS acquired by Assystem Technologies for over £280 million

German company Software Quality Systems (SQS), a provider digital quality assurance services,…