Energy

Energy performance of buildings: BACS decree deadline drawing nearer

The term BACS stands for Building Automation and Control Systems .

Publié le :

30 July 2025

A BACS includes field measurement devices (detectors, sensors, meters, etc.) which transmit data to the system’s automatic control function – without human intervention. The latter then analyzes this data and transmits commands to on-site actuators (electrical controls, contactors, valves, blinds, etc.).

By controlling a number of technical installations, these systems help to reduce energy consumption in buildings, while respecting pre-established setpoints and guaranteeing occupant comfort (setpoint temperature, for example). The aim is to improve the energy efficiency of commercial buildings.

In concrete terms, what functions does the BACS decree require?

The BACS decree requires the installation of an automation and control system in certain commercial buildings. To implement the obligation defined by the BACS decree, i.e. the installation of a BACS in tertiary buildings, two essential parameters must first be defined: what are the functions to be fulfilled? And what uses are involved?

The BACS decree is precise about the functions to be fulfilled. There are five of them:

1. Continuously monitor, record and analyze production (where applicable) and energy consumption data for building systems. This should enable them to be adjusted accordingly, based on setpoints, pre-established scenarios and, above all, possible optimizations. Importantly, this monitoring must be carried out continuously on an hourly basis for each functional zone of the building. A functional zone is a zone within which uses are homogeneous (office zone, for example, or catering zone).
2. Benchmark the building’senergy efficiency(energy audit, energy performance diagnosis, etc.).
3. Detect system inefficiencies (breakdowns, malfunctions, etc.) and alert the operator so he can remedy them.
4. Be technically interoperable (data format, protocols, etc.) with the building’s various technical systems.
5. Enable manual shutdown and autonomous management of systems connected to BACS. Buildings must be able to continue operating normally, even if the BACS needs to be repaired or changed.

What are the “technical systems” mentioned in the BACS decree? Here too, things are very precise. They are :

• Heating system.
• Air conditioning.
• Ventilation.
• Domestic hot water production.
• Integrated lighting.
• On-site electricity generation (via rooftop solar panels, for example).
• And any system that combines several uses.

Energy consumption data must be kept for five years. BACS operators must also be trained in its use.

Some BACS can go even further, for example, by integrating predictive controls linked to weather forecasts, or communicating with the network in order to clear energy consumption. In this way, BACS can cover a very wide range of building management functions.

BACS decree: a new key deadline
from January 1, 2025

The BACS decree is an old one. It dates back to July 2020, with a first entry into force in July 2021. At the time, however, it only applied to new buildings, and even then only to those with a rated output exceeding 290 kW. A new decree published in April 2023 lowered this threshold to 70 kW for new buildings, to come into force one year later, in April 2024.

Timetable for implementation of the BACS decree

5 years

BACS must be inspected every five years at the latest (starting two years after initial installation).

As of January 1, 2025, the obligation to install a BACS also applies to existing buildings with a power rating of over 290 kW. The final deadline of the BACS decree, January 1, 2027, will still apply to existing buildings, but with the power threshold lowered to 70 kW.

The BACS decree provides for an exemption from the obligation when the return on investment time for the installation of a BACS is, after study, greater than 10 years.

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