- Project plans
- Project activities
- Legislation and standards
- Industry context
Last edited 22 Mar 2018
Building services engineer
Building services engineers plan, design, monitor and inspect systems to make buildings comfortable, functional, efficient and safe. Typically these systems will include heating, ventilation and air conditioning (HVAC), water and drainage, lighting, power, ICT, lifts and escalators, control systems, and so on (see Building services for more information).
Building services engineers play a central role in contributing to the design of a building, not only in terms of overall strategies and standards to be achieved, but also in façade engineering, the weights, sizes and location of major plant and equipment, the position of vertical service risers, routes for the distribution of horizontal services, drainage, energy sources, sustainability, and so on. This means that building services design must be integrated into the overall building design from a very early stage, particularly on complex building projects such as hospitals.
While it is usual for a building design team to be led by an architect, on buildings with very complex building services requirements, a building services engineer might be appointed as the lead designer.
Increasingly, building services engineers are also central to the design and assessment of sustainable systems, assessing the life cycle of buildings and their component services to minimise the resources consumed and the impact on the environment during fabrication, construction, operation and dismantling.
According to the Chartered Institute of Building Services Engineers (CIBSE), 'There are around 61,000 firms in this sector, of which 3,000 are design consultancies employing Chartered Engineers. The remainder are mostly manufacturers and contractors, ranging from multi-national companies down to small businesses with a high degree of specialisation. The sector carries out £20 billion of work each year, roughly 3% of UK GNP. In any new construction project, building services typically account for 30 - 40% of the total cost.' Ref. CIBSE fact sheet.
Chartered Engineer (C Eng) status can be granted by the Chartered Institute of Building Services Engineers (CIBSE). Training typically involves a Bachelors (Hons) degree followed by further study or an accredited MEng degree, this is followed by an Engineering Practice Report and then Professional Review Interview. Engineers qualifying by this route can also become members of CIBSE (MCIBSE).
To see some of the modules studied as part of an engineering degree course, see Construction engineering management course essentials.
Alternatively an experiential learning route can be taken, followed by an Engineering Practice Report and then a Competence Review Interview (allowing MCIBSE). Further study and a Professional Review Interview are then necessary to allow C Eng status to be awarded. (Ref. CIBSE membership.)
A search engine is available from the Chartered Institution of Building Services Engineers (CIBSE) to help clients find an appropriate services engineer for their project.
 Characteristics of role
 The dynamic nature of building services engineering systems
Building services engineering systems have to react to both changes in external conditions and the patterns of behaviour inside a building - both of which are constantly changing. The design process is aided by the use of computer models and simulations which can simulate performance with respect to thermal behaviour, energy usage, lighting (daylighting and artificial) outputs, ventilation and renewable energy sources, all with very many variables.
Some aspects of the output of building services engineering design are open to end-user scrutiny and personal judgments. Different people have different comfort levels and tolerances. What constitutes a comfortable thermal environment is a deceptively simple question but has profound implications for building services engineers (see thermal comfort for more information).
Perception also varies according to parameters such as age, gender, the psychosocial atmosphere at work and job stress, making it difficult to satisfy all end-user requirements. Even the perception of having ‘control’ contributes to a person being comfortable over a wider range of conditions such as the amount of daylight, heating and cooling. In addition, there are aesthetic considerations; some occupants will ‘like’ a particular light fitting/tap/radiator whilst others will not.
Controlling the performance of building services is not just a result of the installed building services engineering equipment and their controls. The design will be based on defined patterns of occupancy (density and duration of people in different areas of the building, male/female/disabled ratios), assumptions with respect to portable equipment, and the nature of the finishes, including colour, density, texture and material, to walls, floors and ceilings.
 Design life expectancy
Building services engineering plant, equipment and systems are typically designed to function in a building for 20-25 years. However, in reality, this could be less, due to changes in legislation or as technological advances make them obsolete. This contrasts with structural and civil engineering solutions which are usually designed for a much longer lifespan.
Accordingly, the building services engineering design needs to take into account the likelihood of upgrades or replacement in the future; this includes considering how plant and equipment can be removed from the building, responsibly disposed of, and replaced, whilst still taking into account the ongoing operation of the building during any disruption.
Building services engineering systems are the only active components in an otherwise passive shelter. The ability of the building services engineering systems to continually perform interactively is of vital importance to the operational requirements. When a building is put into use, its building services engineering systems have to perform day-in, day-out for the life of a building and hence require ongoing attention.
 Sequencing of the design process
Despite the prevailing paradigms advocating multidisciplinary working, in reality the architect and structural engineers still tend to lead the process of planning the building, whilst the building services engineering systems are expected to fit into the architectural and structural solutions.
Building services engineers usually produce drawings and a specification to obtain a tender. These should be coordinated with the architectural and structural engineering solutions. Notably, building services engineers do not produce construction or installation drawings.
Their deliverables usually state that these requirements are passed on to subcontractors in terms of design responsibility. In contrast architects and structural engineers usually produce drawings and specifications for contractors and subcontractors to construct, albeit, with details often supplied by specialists.
Building services engineering systems are a major consumer of energy. The current focus on sustainability and the green agenda means that more attention is being paid to this area. This includes the operational efficiency of systems, the selection of materials and managing end-user expectations.
See Performance gap for more information.
 Find out more
 Related articles on Designing Buildings Wiki
- Air conditioning.
- Appointing consultants.
- BSRIA blue book.
- Building Automation and Control System BACS.
- Building energy management systems (BEMS) for data centres.
- Building management systems.
- Building services.
- Chartered Institution of Building Services Engineers (CIBSE).
- Civil engineer.
- Collaborative practices.
- Concept services design.
- Consultant team.
- Electrical engineer.
- Engineering Council.
- Improving visibility and resilience of buried services.
- Insulation specification.
- Lead designer.
- Mechanical and electrical (M&E).
- Mechanical engineer.
- Mechanical ventilation.
- Performance gap.
- Plant room.
- Rules of Thumb - Guidelines for building services.
- Structural engineer.
- The importance of building services.
- Thermal comfort.
- Types of building services.
 External references
- Chartered Institution of Building Services Engineers (CIBSE).
- CIBSE: Design Compass: The CIBSE Design Framework.
- CIBSE: What is building services?
- CIBSE: Directory of practices and firms.
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