- Project plans
- Project activities
- Legislation and standards
- Industry context
Last edited 22 Mar 2018
Building Automation and Control System BACS
The term 'Building Automation and Control System' (BACS) refers to centralised systems that monitor, control, and record the functions of building services systems. Building facilities that are monitored and controlled by a reliable BACS tend to maintain the building environment more efficiently and so reduce the building's environmental impact and energy costs.
The core functions of a BACS system are as follows:
- Maintain control of the building's environment.
- Operate systems according to occupancy and energy demand.
- Monitor and correct the performance of systems.
- Sound alerts as required.
The facilities that may be controlled by a BACS system include:
- Mechanical systems.
- Electrical systems.
- Heating, ventilation and air-conditioning (HVAC).
- Lighting control.
- Security and surveillance.
There is growing overlap between the concepts of BACS and the need to learn from the accumulated data to operate buildings more efficiently. Increasingly this includes technologies such as the internet of things to become smart buildings.
The basic components of a BACS are:
- Sensors: Measure values such as temperature, humidity, lighting levels, room occupancy, and so on.
- Controllers: Instigate the system's response from the collected data, using algorithms that apply logic and send commands.
- Output devices: Carry out commands from the controller.
- Communications protocol: The 'language' used by the BACS components.
- Dashboard: The user interface for data reporting and interaction with the BACS system.
There are a number of similar terms that can be used to refer to building automation, such as Building Management System (BMS), Building Control System (BCS) and Building Automation System (BAS). However, BACS is the standard term as defined by EN ISO 16484-2:2004 Building automation and control systems (BACS) -- Part 2: Hardware, 3.31.
BMS and BCS are general terms for systems that control a building's facilities. However, unlike BACS, they are not necessarily automation systems.
The phrase Building Energy Management Systems (BEMS) is sometimes used interchangeably with BACS, however, BEMS deal specifically with energy consumption, metering, and so on. It is generally considered though that there is sufficient overlap between the two that they can be used interchangeably.
 Related articles on Designing Buildings Wiki
- Air conditioning.
- Building Automation and Control System Market.
- Building energy management systems BEMS.
- Building management systems.
- Building services.
- 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.
- Parking reservation systems.
- Plant room.
- Smart buildings.
- US Smart Connected HVAC in Commercial Buildings Study 2017.
- Wireless vs wired building energy management system.
 External resources
- Control Your Building - The ultimate guide to building automation
Featured articles and news
Which room is the most fun to design? Find out the 'Grand Designs' presenter's unusual choice in our interview.
Full suite of speakers are announced for this year's BSRIA Briefing event.
Book your place for the Architectural Technology Awards 2018.
There are many ways of classifying types of building. Have a look at our range of building articles.
BSRIA have launched the 'major update' of the go-to design framework guide for building services.
How to get results with building life cycle assessment.
Government publishes a prospectus inviting proposals for new 'garden communities'.
The Morandi motorway bridge in Genoa collapses during rainstorm while undergoing maintenance works.
'Developed design' is a phrase coined by the RIBA for their 2013 Plan of Work. But what does it actually mean?
New green paper published aiming to rebalance the relationship between landlords and residents and tackle stigma.
RIBA calls for a comprehensive ban on combustible materials.