GACS Compliance: Turning Regulation into Smart Building Performance
- Anicka Tatari
- Jan 14
- 3 min read
Europe’s energy transition is accelerating, and buildings are right at the centre of it.
From 1 January 2026, large non-residential buildings will be required to operate with an intelligent Building Automation and Control System (GACS). Not as a box-ticking exercise, but as a concrete step towards lower energy use, better comfort and future-proof building operations. At Montreal Solutions, we see GACS not as an obligation, but as an opportunity: to make buildings smarter, more efficient and ready for what’s next. In this article, we explain what GACS really means, who it applies to and how to take the right next steps.
What is GACS?
A GACS (Building Automation and Control System) is the digital backbone of a modern building. It connects and intelligently manages technical installations such as:
Heating, ventilation and air conditioning (HVAC)
Cooling systems
Lighting and other building-related systems
Instead of operating in isolation, these systems continuously exchange data. The GACS analyses performance and energy consumption in real time and automatically optimises settings where possible.
Think of GACS as the brain and nervous system of your building: always monitoring, learning and adjusting to ensure optimal performance, comfort and efficiency.
Who must comply – and when?
he obligation is introduced in phases:
From 2026
All non-residential (utility) buildings with heating or cooling systems with a nominal capacity of 290 kW or more.
This includes buildings such as:
Office buildings
Hospitals and healthcare facilities
Shopping centres
Large commercial and industrial buildings
From 2030
The threshold is lowered to 70 kW, bringing many smaller buildings into scope, including:
Schools
Sports facilities
Smaller offices and public buildings
This phased approach gives building owners time to prepare, while clearly signalling that smart automation will become the new standard.
What must a GACS be able to do? (Minimum Level C)
Under the European EPBD (Energy Performance of Buildings Directive), a compliant GACS must achieve at least Level C functionality. This means the system must be able to:
1. Monitor and store energy data
Continuously track energy consumption, store data securely and make it accessible for review and reporting.
2. Analyse performance
Assess the efficiency of installations, detect deviations or faults and generate actionable insights to improve performance.
3. Control and optimise automatically
Actively adjust system settings to improve efficiency and comfort — for example by reducing output during low-occupancy periods.
4. Ensure interoperability
Communicate with systems from different manufacturers, avoiding vendor lock-in and enabling flexible integration now and in the future.
Why is GACS mandatory?
Buildings account for a significant share of Europe’s energy use and CO₂ emissions. Making smart automation mandatory is a logical step towards achieving climate targets.
But compliance is only part of the story. A well-implemented GACS delivers tangible benefits:
Lower energy costs Better insight and control lead directly to reduced consumption and operational savings.
Improved indoor comfort Stable temperatures, better air quality and fewer complaints from users.
Future-ready buildings Compliance with the latest standards increases asset value and prepares buildings for upcoming regulations and technologies.
Determining the right GACS level for your building
The NEN-EN-ISO 52120 standard defines performance levels for building automation systems. The first step is a thorough inventory of:
Existing installations
System capacities
Current energy performance
This assessment determines which GACS level is required and what upgrades are necessary.
In the Netherlands, the RVO checklist can be used as a practical tool to assess compliance and support system selection and implementation.
Practical implementation tips
To avoid last-minute pressure, we recommend:
Start early – Assess your building well before 2026
Work with specialists – GACS is as much about strategy as it is about technology
Choose open systems – Flexibility and interoperability are key
Train users and operators – Technology only works if people know how to use it
Plan maintenance and updates – Continuous optimisation requires ongoing attention
In summary
GACS compliance marks a decisive shift towards smarter, more sustainable buildings. From 2026, large non-residential buildings must operate with intelligent automation capable of monitoring, analysing and optimising energy use. From 2030, this requirement extends to many smaller buildings as well.
By acting early and choosing the right approach, building owners can turn regulation into real value: lower costs, better comfort and a future-proof asset. At Montreal Solutions, we help organisations move beyond compliance — towards intelligent building performance.
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