About the job:
As a Senior Project Engineer – Mechanical, you will play a key role within Ethos’ Data Centre team, with a focus on retrofit projects across mission-critical data centre environments.
You will lead the design, specification and delivery of mechanical systems, ensuring projects are delivered safely, efficiently and to the highest technical standards. Working within live environments, you will help maintain continuity of operations while delivering high-quality engineering solutions.
This role will also involve managing project delivery, mentoring junior engineers and acting as a key technical point of contact for clients and contractors across major European data centre markets.
Your day-to-day activities:
Lead the design and delivery of mechanical building services upgrades within live data centre environments, including M&E upgrades, capacity increases, technology refreshes, phased refurbishments, and lifecycle replacements.
Develop and manage retrofit-specific design strategies, including tie-ins to live systems, redundancy planning, outage and staging strategies, and resilience design.
Conduct or oversee technical due diligence of existing data centre facilities, including capacity unlock assessments (power, cooling, and white space).
Prepare and review detailed design drawings, schematics, schedules, technical reports, and tender documentation.
Manage project scope, budget, programme, and contracts — identifying and mitigating scope creep, risks, and live-environment constraints.
Liaise directly with clients (hyperscale, colocation, and enterprise operators), contractors, and vendors to ensure project goals are achieved with zero operational disruption.
Drive quality assurance and governance across all assigned projects, adhering to WAP/PTW protocols in live environments.
Mentor and support the development of junior engineers and graduate staff within the retrofit workstream.
Support business development by contributing to proposals, client presentations, and technical strategies for retrofit opportunities across EMEA.
Champion innovation in live-environment engineering and contribute to the continuous improvement of Ethos’ retrofit delivery model.
Lead phasing strategy for live cooling and HVAC upgrades, ensuring continuity of critical mechanical infrastructure throughout delivery.
About you:
Strong expertise in mechanical systems design for live data centre environments, including chilled water plant, CRAC/CRAH upgrades, air handling units, in-row cooling, and fire suppression systems.
Experience delivering M&E upgrades within operational facilities — including tie-ins to live plant, outage management, and resilience planning.
Proficient in AutoCAD, Revit MEP, Bluebeam, and Microsoft Office; working knowledge of IES, HAP, or similar mechanical analysis tools is advantageous.
Strong knowledge of CIBSE, ASHRAE, BS, IS, and EN standards applied in retrofit and live-environment contexts.
Understanding of PUE optimisation and cooling efficiency improvements to meet EU Energy Efficiency Directive targets and client ESG requirements.
Familiarity with commissioning and integration of mechanical systems within live, mission-critical facilities.
Bachelor’s or Master’s degree in Mechanical Engineering or a related discipline.
Minimum 8 years’ experience in building services engineering, with at least 3 years focused on data centre or mission-critical projects.
Demonstrable experience working in live, operational data centre environments — including brownfield upgrades, M&E replacements, or phased refurbishments.
Chartered Engineer status (or actively working towards Chartership) with Engineers Ireland or equivalent.
Proven track record managing multi-million-euro MEP projects from concept to completion.
Strong understanding of Irish and EU building regulations; knowledge of LEED/BREEAM and the EU Energy Efficiency Directive is an advantage.
Excellent communication and presentation skills, with confidence in client-facing settings.
Strong organisational and problem-solving abilities, capable of managing multiple concurrent retrofit projects.
Collaborative approach to working across multidisciplinary teams including mechanical, electrical, sustainability, and BIM disciplines.
Proactive, detail-oriented mindset with a sharp focus on risk management and technical quality in live environments.
Calm under pressure — able to make sound engineering decisions within constrained, operational environments.
At Ethos, we’re dedicated to fostering an environment that encourages both technical excellence and personal wellbeing
We offer:
Flexible Fridays and a 9-day fortnight working schedule — enjoy every second Friday off to maintain work–life balance.
A culture that values flexibility, learning, and teamwork, with clear progression pathways and support toward professional accreditation
Opportunities to work alongside some of the most experienced engineers in the industry, within a forward-thinking, technology-driven consultancy.
Benefits:
Flexible working times / Hybrid Working
20 days of holidays
Pension Scheme
Coverage for working travel out-of-pocket expenses
Regular training, mentoring, and further college support
Support for Chartership
A professional subscription fee paid by the company
Heavily subsidized social committee activities (5-a-side football, golf society, climbing club, and regular social events)
Ethos is a team of collaborative and creative consultant engineers & professionals, leading data centre and energy infrastructure projects globally.
Our Charter:
We believe in strong human relationships
We believe clear leadership lights the path
We believe sustainability is non-negotiable
We believe a can-do mindset can move mountains
We believe in a relentless focus on delivery
Our Tagline:
Performance Made Possible
Ethos Engineering (2005) deliver high-performance mechanical and electrical (M&E) engineering solutions across Ireland and EMEA. Our expertise spans data centres, commercial, offices, and high-tech environments, with services in design & project management, sustainability, smart buildings, and M&E systems for building services.
At Ethos, our EPIC-F values—Excellence, People, Innovation, Clients, and Financial Strength—drive everything we do. We provide bespoke solutions that not only meet regulatory standards but also deliver long-term value through innovation and sustainability.
Our Design & Project Management service offers full oversight from concept to completion, coordinating all project disciplines including mechanical, electrical, civil, and architectural design. With a focus on scope, time, cost, quality, and risk management, we ensure optimal productivity and value engineering throughout the process, tailored to the client needs.
Our Sustainability Services empower clients to meet stringent environmental standards. From energy modelling and whole-life carbon assessments to net zero carbon roadmaps and ESG frameworks, we help reduce carbon emissions and ensure compliance with global sustainability benchmarks like LEED, BREEAM, and GHG reporting. Focusing on your long-term sustainability goals.
Our Digital/Smart Buildings team transforms spaces into intelligent ecosystems. Focusing on sustainability, user experience, productivity, physical security, and efficiency, we integrate digital technologies like IoT, digital twins, and advanced analytics to optimise building performance. We ensure buildings interact seamlessly with people and systems, delivering exceptional results now and in the future.
Ethos’ expansion across EMEA, has been enabled by our ability to create spaces that bring buildings to life. Our methodology involves designing buildings that not only perform today but ones that contribute to the sustainable, green, and circular economy of tomorrow.
