Buildings Guide

Building Energy Management

Key Message

Building Energy Management (BEM) is a systematic process to monitor, control and benchmark the energy consumption of a building and its systems, to implement energy efficiency improvement actions, and to optimise the operation of the building in order to minimise energy use. These systems control, monitor and optimize energy consumption of comfort systems, lighting, hot water and appliances in a building over time and augment energy savings already obtained by the use of passive and active measures. An important tool for BEM is Building Automation & Control systems (BAC)/Building Energy Management systems (BEM), which is the focus of this bigEE section. By complying to ‘Class A’(high energy performance) classification of the standard EN 15232 (Energy performance of buildings - Impact of Building Automation, Controls and Building Management) there can be potentially up to 30% energy and cost savings with added benefits of thermal comfort and safety (Siemens, 2010). Other studies show that by employing building automation and energy management techniques 60% of annual energy savings could be obtained with a pay back period of 2-10 years in commercial buildings (Becker, Bollin & Eicker, 2010).


With the increased number of service systems and appliances in modern buildings, it has become a complex task to manually overlook and control all of them. This potentially results in mix-ups, negligence and human error and thus lead to unwarranted energy wastage. State of the art intelligent buildings aid passive heating, cooling, natural ventilation and daylighting through sophisticated controls by responding to both building’s internal and external environment dynamically. They enable efficient daylight penetration, provide glare control, and optimize the use of heating, ventilation and air conditioning systems, lighting systems and equipment in a building by using demand response and load management technologies while ensuring human comfort at minimum energy consumption levels possible.


At least some degree of deploying Building Energy Management in service sector buildings like office, hotel, retail and other multi-functional buildings is gaining ground worldwide, especially making quick foray in rapid growth markets of Asia Pacific. In residential buildings, building automation and energy management is acquiring popularity in Europe and USA, which already have a market for sophisticated energy, and appliance systems in residences, while it is almost unheard of in the residential sector in rest of the world.


The growth of the BMS market has been extremely large in recent years. It is estimated that the revenue growth of smart HVAC control market for various products and components (sensors, controllers and actuators) reaches €14.52 ($26.60) billion by 2020 at an estimated Compound Annual Growth Rate of 8.22% from 2014 to 2020. Owing to the rate of construction and development activity in the Asia Pacific region, it leads the smart HVAC controls market, which is followed, by the Americas and Europe (MarketsandMarkets.com, 2014).


Typical Building Energy Management (BEM) installation would have three main constituents. They are sensors, a logical monitoring and control unit and actuators. The operation of a BEM system is a three step process. Sensors are attached to all the systems that need to be monitored and controlled and the data is relayed to monitoring and control system. Monitoring and control system continuously evaluates the performance of various systems and sends out signals to actuators to take any necessary action. This enables live controlling of devices through actuators and also enables to continuously monitor energy consumption data by its end use.

Simple layout of building automation and energy management systems


Sriraj Gokarakonda
Christopher Moore


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