EU EPBD 2024: building automation and indoor environmental quality

Directive (EU) 2024/1275 recasts the Energy Performance of Buildings Directive (EPBD). Article 13 sets a common direction for building automation, indoor environmental quality and automatic lighting control. It does not create one identical installation rule for every building in Europe. Member States implement the Directive through national law, and those national rules define the enforceable scope, exemptions, evidence and inspection process.

That distinction matters for projects planned across several countries. France already applies a 70 kW BACS regime with a defined timetable and a separate CEE funding route for qualifying GTB work. Germany has enacted a 70 kW requirement in its Building Energy Act. Ireland and Italy have national rules for parts of the stock above 290 kW while later stages still need to be read from current national measures. A European portfolio can use one technical evidence model, but it cannot use one legal checklist without checking each jurisdiction.

Which non-residential buildings Article 13 covers

Article 13(9) tells Member States to require BACS, where technically and economically feasible, for non-residential buildings whose covered systems have an effective rated output:

The covered systems are heating, air-conditioning, combined space heating and ventilation, and combined air-conditioning and ventilation. The threshold is not the building's electrical connection, annual energy use, floor area or sum of every load in the building.

For each site, retain the equipment schedule, nameplate ratings, system arrangement and calculation used to determine effective rated output. Record whether several generators form one system and how duty and standby plant were treated. If a project relies on technical or economic infeasibility, retain the national test and the dated evidence used to reach that conclusion.

The 31 December 2024 stage reflects a requirement already present under the earlier EPBD. The recast adds the 70 kW stage. A missed 2024 national deadline does not become a future requirement merely because a project begins later. Check the current national position and any enforcement or remediation process.

What the BACS must be capable of

Article 13(10) defines outcomes for the complete building automation and control system. It must be capable of:

1. continuously monitoring, logging and analysing energy use, and allowing energy use to be adjusted;
2. benchmarking the building's energy efficiency, detecting losses in the efficiency of technical building systems, and informing the person responsible for facilities or technical building management about improvement opportunities;
3. communicating with connected technical building systems and appliances, and operating across different proprietary technologies, devices and manufacturers; and
4. monitoring indoor environmental quality.

The Commission's implementation guidance says the first three capability groups could correspond to Class B BACS under EN ISO 52120-1. The word "could" is important. Use the standard as a structured way to assess functions and gaps. Do not treat a class label on one controller as proof that the building, its connected systems and its operating process meet national law.

A complete design maps each Article 13 outcome to equipment, software, data and an accountable person. For example, a power meter can measure chiller input, a controller can expose run state and set point, an analytics service can detect a rising kWh per unit of cooling, and a work process can assign the resulting alarm. No single component establishes the complete outcome.

Adjustment does not mean uncontrolled remote access

The ability to adjust energy use should be designed through the plant's documented control hierarchy. Safety, equipment protection, anti-cycle logic and local limits remain in the manufacturer-approved controller. A supervisory BACS may request an operating mode, schedule or bounded set point through a documented interface.

Start read-only. Confirm object or register identity, unit, data type, timestamp and quality against the local display and an independent measurement. Enable writes only after the manufacturer identifies the writable point, priority or command path; the building operator approves the control boundary; and communication loss, rejected commands and local override have safe outcomes. Record commanded state and achieved state separately.

Indoor environmental quality and the 2026 transposition date

The recast adds indoor environmental quality monitoring to the BACS capabilities. Article 13(10)(d) required this capability by 29 May 2026 for buildings covered by Article 13(9), subject to the Directive's technical and economic feasibility condition. Member States had to implement the provision in national law by that date, and their measures determine how it applies in practice.

The Directive does not prescribe one universal sensor pack. Choose parameters and locations from the occupied space, its use and the technical systems being assessed. A useful plan may include:

• temperature and relative humidity in representative occupied zones;
• carbon dioxide where occupancy and ventilation performance make it a useful indicator;
• other pollutants or comfort parameters where the activity and national guidance justify them;
• occupancy or a defensible schedule, so conditions can be interpreted in context;
• ventilation, heating and cooling states serving each monitored zone.

Define the acceptable range, sampling interval, retention period, quality state, alarm threshold and response owner for every point. A plant-room sensor does not represent conditions across offices, classrooms or retail areas. An average can also conceal one persistently poor zone, so retain zone-level values where the system design calls for them.

IEQ monitoring is not a licence to reduce comfort in pursuit of energy savings. Use it to show whether energy and operating changes maintained the agreed conditions. If a control action reduces consumption while temperature or air quality moves outside its band, the result is not a demonstrated efficiency improvement.

Automatic lighting controls are a separate stage

Article 13(12) requires Member States to set automatic lighting-control requirements, where technically and economically feasible, for non-residential buildings with the same categories of covered heating and cooling systems:

The controls must be suitably zoned and capable of occupancy detection. This is a separate requirement from installing a BACS. A BACS project should coordinate the lighting-control zones, occupancy signals, schedules and energy measurements, but it should not claim the lighting stage is satisfied merely because the BACS can display a lighting circuit.

National implementation may define system boundaries, exceptions, commissioning and inspection in more detail. Check those measures before specifying coverage or accepting a project.

Residential monitoring and control

Article 13(11) also requires Member States to set requirements for certain new residential buildings and residential buildings undergoing major renovation, where technically, economically and functionally feasible. The functions include continuous electronic monitoring that measures system efficiency and informs owners or managers of significant variation and servicing needs, effective control of energy generation, distribution, storage and use, and the capacity to react to external signals.

Member States may exclude single-family houses undergoing major renovation where installation costs exceed the benefits. National law determines how the requirement applies in practice. Do not carry the non-residential 70 kW threshold into a residential assessment or assume that one domestic product configuration is sufficient in every country.

Build an evidence model that works across a portfolio

A common evidence model reduces repeated engineering without pretending the law is identical.

Commission the chain with known conditions. Compare energy totals with an independent reference. Change a permitted schedule or set point and verify the plant response. Create a defined alarm, interrupt communications and confirm that stale data is visible and recovery is recorded. Test that another system receives the required values with units, timestamps and quality states.

Do not replace missing values with zero or carry the last value forward without a quality flag. Either choice can turn a communications failure into false evidence. Keep raw measurements, calculated indicators, operator annotations and control events distinct.

Check the national rule before making a compliance claim

The EPBD's transposition deadline for the relevant provisions was 29 May 2026. Transposition is not the same as uniform implementation. A national measure can define the threshold calculation, feasibility test, deadline path, competent inspector, maintenance duties, evidence retention and penalties.

Before procurement, answer these questions from the current national text:

1. Which building uses and technical systems are in scope?
2. How is effective rated output calculated for multiple generators or systems?
3. Which date applies to an existing building, replacement project or new permit?
4. How are technical and economic feasibility tested and documented?
5. Which BACS, IEQ and lighting functions apply now?
6. What inspection, maintenance, training and record-retention duties apply?
7. Who owns the obligation and which authority enforces it?

Our French BACS guide, German GEG guide, Irish BACS guide and Italian BACS guide apply this method to current national sources.

Where EpiSensor fits

EpiSensor provides an operational measurement and integration layer around existing building plant. Electricity monitors can separate heating, cooling, ventilation, pump and lighting feeders. Pulse and M-Bus interfaces can collect gas, water and heat-meter totals. Modbus and analogue interfaces can bring documented controller states and process measurements into Edge. A Gateway can retain the record on site and serve collected data onward over Modbus TCP, MQTT or HTTP.

That can close measurement gaps, connect older equipment and provide independent evidence to a wider BMS. It does not make a building compliant by itself. The complete installation must provide every applicable national function, cover the required systems and zones, and pass the required commissioning, maintenance or inspection process.

Use the HVAC energy-monitoring application to define plant boundaries, then the BMS and SCADA integration application to plan the data path. Keep compliance sign-off with the building owner, designer and competent national specialist.