- Project plans
- Project activities
- Legislation and standards
- Industry context
Last edited 26 Aug 2018
Building energy management systems BEMS
Building Energy Management Systems (BEMS) are integrated, computerised systems for monitoring and controlling energy-related building services plant and equipment such as heating, ventilation and air conditioning (HVAC) systems, lighting, power systems and so on.
The phrase Building Energy Management Systems is sometimes used interchangeably with Building Management Systems (BMS), however, strictly speaking, Building Management Systems can be used to monitor and control a wide range of building systems, including fire, smoke detection and alarms, motion detectors, CCTV, security and access control, lifts and so on. Building Energy Management Systems relate specifically to energy-related systems.
Small buildings may have independent controls for energy systems, but for larger or more complex buildings, sites with a number of buildings, or organisations with buildings on a number of sites, the integration of systems operation through a single Building Energy Management System offers greater control and can achieve significant savings. NB Increasingly, simple BEMS are being developed that are suitable for even the smallest buildings.
BEMS provide real-time remote monitoring and integrated control of a wide range of connected systems, allowing modes of operation, energy use, environmental conditions and so on to be monitored and allowing hours of operation, set points and so on to be adjusted to optimise performance and comfort. BEMS can also trigger alarms, in some cases predicting problems and informing maintenance programmes. They allow records to be kept of historical performance, enable benchmarking of performance against other buildings or sites and may help automate report writing.
In 2014, BSRIA reported that the global BEMS market was worth $3.5 billion, or 3 billion Euros, and was growing globally at more than 10% per annum. This increasing interest has resulted from the rising cost of fuel, concerns over energy security, increasingly aggressive environmental targets and the reduced cost of sensors, analytics software and data storage.
Claims for the scale of savings that can be achieved by BEMS range from 10% to 25%. Operated properly, they should allow energy use to be optimised without compromising comfort or performance. However this requires a thorough understanding of how buildings are supposed to perform, and how different systems within them interact.
To function correctly they must be properly designed, installed and commissioned and must have a user interface that is easy to operate. They should then be continually assessed and fine-tuned as performance is better understood over a number of seasons and modes of operation, and changes are made to buildings or operations. Maintenance is also necessary to ensure systems continue to operate correctly, for example, replacing sensors and batteries, checking connections, checking the operation of dampers and valves, upgrading software and so on.
BEMS can be independent installations with separate maintenance contracts, or manufacturer installations which include maintenance. They can be wired or wireless systems. To determine whether a wired or wireless system is the most appropriate, buildings should be audited to test how well signals can be received and how likely disturbances are. Choosing the correct BEMS system then depends on the size and usage of the building, the scale of the project and the budget. As a general rule, larger, more extensive projects tend to be best suited to wireless solutions.
BEMS may have remote outstations that can be interrogated locally, or may be accessible from mobile devices. However, major buildings may be vulnerable to cyber attack, especially when they are associated with prominent organisations. This can be a particular issue where functions operate in the 'cloud', such as cloud-based analytics, and the ability to access and manage multiple buildings remotely. The ability to access live analytics, or receive alarm notifications from hand-held devices has great potential benefits, but may also bring additional risks.
 Find out more
 Related articles on Designing Buildings Wiki
- Air conditioning.
- Building Automation and Control System BACS.
- Building energy efficiency - is building automation the answer?
- Building energy management systems (BEMS) for data centres.
- Building management systems
- Building services.
- Building services engineer.
- Commercial building automation market.
- Cyber threats to building automation and control systems.
- Energy management and building controls.
- Global building energy management systems market.
- Internet of things.
- Mechanical, electrical and plumbing MEP.
- Smart buildings.
- Smart meter.
- Smart technology.
- US Smart Connected HVAC in Commercial Buildings Study 2017.
- Wireless vs wired building energy management system.
Featured articles and news
When is there a right to light, and what happens if it is obstructed?
What would the nationalisation of economic infrastructure mean for GB?
A new guide to improving value by reducing design error.
We've reached 80,000 page views a day and 10,000 registered users. Why not join them?
A masterplan is a framework within which a location is encouraged to develop or change. Read our introductory article.
New consultation announced on a specialist Housing Court to settle landlord-tenant disputes.
ICE responds to a transport consultation advising the government to make decisions enabling more inclusive cities.
BRE and Loughborough University complete first phase refurbishment of demonstration home.
How the risk of collapse of fibrous plaster ceilings is being addressed in theatres.
If you’re a great writer and have practical experience of the construction industry, it could be you.
Frustrated by long documents or technical jargon? Put off by sign-up forms or costs? Take this 5 min survey to help improve construction knowledge.