Smart Building Glossary

A building management system (BMS) is supervisory software that monitors and commands HVAC, lighting, power, fire, and security plant from one operator interface. Field sensors and actuators connect to DDC controllers on BACnet or Modbus; the BMS server aggregates trends, alarms, schedules, and integrations to CMMS, energy, and BIM. Integrators often pair a BMS with IoT overlays (LoRaWAN, MQTT) for retrofits. See the CONTEXUS BMS guide for architecture and open source options.

A building automation system (BAS) is the control layer that executes HVAC and lighting logic on DDC controllers — schedules, interlocks, PID loops, and safeties. BAS is often used interchangeably with BMS in marketing, but technically BAS refers to field control while BMS refers to the supervisory server and operator UI that sits above multiple BAS subnets.

A building energy management system (BEMS) focuses on meter data, submetering, tariff analysis, demand response, and audit-ready reporting — often aligned with ISO 50001 and portfolio ESG disclosures. BEMS complements a BMS: the BMS optimizes plant operation while the BEMS verifies savings and feeds owner reporting.

Heating, Ventilation, and Air Conditioning — the technology of indoor environmental comfort that provides thermal comfort and acceptable indoor air quality.

A virtual representation of a physical building that uses real-time data from sensors and other sources to mirror the building's actual state and behaviour.

A network of physical devices, sensors, and other items embedded with electronics, software, and connectivity that enables data collection and exchange.

Long Range Wide Area Network — a low-power, wide-area networking protocol designed to wirelessly connect battery-operated sensors and devices over long distances.

Building Automation and Control Networks — a communication protocol for building automation and control systems that allows interoperability between different manufacturers' equipment.

A serial communication protocol used for connecting electronic devices, commonly used in building automation for communication between controllers and sensors.

Message Queuing Telemetry Transport — a lightweight publish/subscribe messaging protocol widely used to connect IoT devices and stream telemetry over unreliable or low-bandwidth networks.

OPC Unified Architecture — a platform-independent service-oriented protocol that securely exchanges industrial automation data between servers, clients, and BMS/SCADA systems.

A device that detects the presence of people in a space and can trigger automated responses such as lighting control or HVAC adjustments.

A system of computer-aided tools used to monitor, control, and optimise the performance of building energy consumption.

Maintenance strategy that uses data analysis and machine learning to predict when equipment will fail, allowing maintenance to be performed just in time.

Computerised Maintenance Management System — software that centralises maintenance information and facilitates the processes of maintenance operations.

Software that unifies IT and facility management of a data centre — measuring power, cooling, capacity, and PUE to support uptime and capacity planning.

A ratio defined by The Green Grid that divides total data centre facility power by IT equipment power. A PUE of 1.0 is ideal; legacy sites often run 1.8–2.0, modern sites 1.2–1.3.

A commercial HVAC technology that uses refrigerant as the cooling/heating medium and lets a single outdoor condenser serve multiple indoor units with individualised temperature control.

A device used to regulate and circulate air as part of an HVAC system, typically containing heating/cooling elements, filters, and fans.

A simple device consisting of a heating/cooling heat exchanger and fan that recirculates room air, commonly used to zone individual rooms in commercial HVAC.

A type of HVAC system that varies the airflow at a constant temperature to meet the thermal load of a space.

A digital representation of physical and functional characteristics of a facility, serving as a shared knowledge resource for building information across design, construction, and operations.

The extension of 3D BIM with 4D construction scheduling, 5D cost management, 6D sustainability analysis, and 7D facility lifecycle operations — carrying one model from design through the operations phase.

An open, vendor-neutral data schema maintained by buildingSMART for describing building and construction industry data. IFC is the most widely used open standard for exchanging BIM models.

Processing data near the source of data generation rather than in a centralised cloud, reducing latency and bandwidth usage in building systems.

A set of protocols and tools for building software applications that enable different systems and platforms to communicate with each other.

Supervisory Control and Data Acquisition — a system for remote monitoring and control of building equipment and processes.

The air quality within and around buildings and structures, especially as it relates to the health and comfort of building occupants.

An electronic device that records consumption of energy in intervals and communicates that information for monitoring and billing purposes.

Changes in electric usage by end-use customers from their normal consumption patterns in response to changes in the price of electricity over time.

Automated processes that identify and diagnose faults in building systems to improve operational efficiency and reduce energy waste.

A building that produces as much energy as it consumes over the course of a year through renewable energy sources and energy-efficient design.

Leadership in Energy and Environmental Design — a widely used green building rating system that provides a framework for healthy, efficient, and cost-saving green buildings.

The American Society of Heating, Refrigerating and Air-Conditioning Engineers publishes standards such as ASHRAE 90.1 (energy) and ASHRAE 62.1 (ventilation) used to benchmark chiller, AHU, and building performance. CONTEXUS AI Analytics compares uploaded BMS data against ASHRAE baselines for COP, kW/RT, and efficiency ratios.

ISO 50001 is the international energy management systems standard. It provides a Plan-Do-Check-Act framework for establishing energy baselines, targets, and audit trails. Building energy management platforms support ISO 50001 with submetering, M&V reporting, and documented control changes.

Environmental, Social, and Governance reporting for real estate portfolios typically discloses energy use, carbon emissions, water, and waste from building operations. IoT submetering and BEMS data feed GRESB, CDP, and owner sustainability reports when meters and boundaries are mapped correctly.

Property technology — software and hardware that improves how buildings are managed, leased, or experienced. Open source smart building platforms let PropTech firms and system integrators white-label IoT, energy, and analytics modules instead of building proprietary stacks from scratch.

The measurement and analysis of how effectively physical spaces within a building are being used, often tracked through sensors and analytics.

A company that designs, installs, and maintains building automation, IoT, or IT systems for end clients. CONTEXUS is built for system integrators who deliver white-label smart building solutions without funding their own R&D.

A software product a partner can rebrand as their own — including logo, colours, and domain — so end clients see the partner's brand throughout the experience. CONTEXUS Certified and Premier tiers include white-label rights.

Cloud-hosted software that ingests IP camera streams, records and replays footage, and provides live monitoring, search, and AI analytics — without requiring on-premise NVR or DVR hardware.

Open Network Video Interface Forum — an open industry standard that lets IP cameras, NVRs, VMS platforms, and video analytics from different vendors interoperate over a network.

A ratio of useful heating or cooling provided by a chiller or heat pump to the electrical energy it consumes. CONTEXUS AI Analytics benchmarks chillers against ASHRAE COP targets.

Kilowatts per refrigeration tonne — an efficiency metric for chillers expressing power input per unit of cooling output. Lower kW/RT means a more efficient chiller.