A building services engineer (also called an M&E engineer) designs and specifies the mechanical and electrical systems that make a building function and comfortable. Their scope encompasses heating, ventilation and air conditioning (HVAC), hot and cold water services, drainage, electrical distribution, lighting, fire detection and alarm, emergency lighting, lifts and building management systems (BMS). On new-build and refurbishment projects they are responsible for demonstrating compliance with Building Regulations Part L (energy efficiency), Part F (ventilation), Part E (acoustics) and Part B (fire) as they apply to services installations.
What they do
- Design HVAC systems (heating, ventilation and air conditioning)
- Design hot and cold water services, drainage and sanitary pipework
- Specify electrical distribution boards, wiring and power layouts
- Design lighting systems and produce lighting calculations
- Specify fire detection, alarm and emergency lighting systems
- Produce M&E specifications and drawings for contractor tender
- Carry out Part L energy compliance modelling (SAP, SBEM, DSM)
- Coordinate with structural and architectural teams on service routes
When you need one
A building services engineer is needed on any project where M&E systems need to be designed, specified or coordinated - particularly commercial fit-outs, new build and complex refurbishments.
Typical costs (UK, 2025)
| Job type | Typical cost |
|---|---|
| M&E specification - small commercial project | £1,500 - £5,000 |
| Full M&E design - office fit-out (500 m²) | £8,000 - £25,000 |
| Full M&E design - new build commercial | £20,000 - £100,000+ |
| Part L compliance modelling (SBEM) | £2,000 - £6,000 |
| SAP assessment (residential) | £400 - £1,200 |
| Hourly rate (Chartered Building Services Engineer) | £75 - £145 / hr |
M&E design fees are often calculated as a percentage of the M&E works value (typically 5-10% for commercial projects). Fees vary significantly with project complexity and the scope of services included.
Qualifications to look for
The primary professional qualification for building services engineers in the UK. Requires a recognised degree in building services, mechanical or electrical engineering, relevant experience and a professional review. CIBSE also maintains a register of Low Carbon Consultants (LCC) and Low Carbon Energy Assessors (LCEA). Check membership at cibse.org.
Many electrical building services engineers hold IET chartership. The IET is the professional body for electrical, electronic and IT engineering and is widely recognised for electrical M&E specialists. Check membership at theiet.org.
How to find a reputable building services engineer
Related Calculators
Extension Cost Calculator New Build Cost Calculator Commercial Build Cost CalculatorFrequently asked questions
What does a building services engineer design?
A building services engineer designs the mechanical and electrical systems that make a building function - heating, ventilation and air conditioning (HVAC), hot and cold water plumbing, drainage, electrical power distribution, lighting design, fire detection and alarm systems, emergency lighting, lifts and escalators, access control and building management systems (BMS). On larger projects they also coordinate energy strategy and Part L compliance modelling.
When do I need a building services engineer?
You need a building services engineer for any commercial or large residential project requiring M&E design and specification. This includes office fit-outs, new commercial buildings, schools, hospitals, hotels, large apartment blocks and complex residential extensions. Building Regulations Part L (energy efficiency), Part F (ventilation) and Part E (sound) all have M&E implications that a building services engineer addresses.
What qualifications should a building services engineer have?
Look for Chartered Member of CIBSE (MCIBSE) or Fellow (FCIBSE) - the Chartered Institution of Building Services Engineers is the primary professional body. Mechanical specialists may hold CEng MIMechE (Institution of Mechanical Engineers) and electrical specialists CEng MIET (Institution of Engineering and Technology). Always confirm Professional Indemnity Insurance.