BACS: what is it and where are the opportunities?

The rules around energy management are changing fast. Where you may have managed with scattered reports and reactive control until now, a new obligation is coming: BACS. From 2026, large buildings must have a Building Automation and Control System. It sounds technical, but the impact will be directly felt by anyone responsible for energy, real estate or facilities.

In this blog we explain what BACS actually means, why the obligation has been introduced and what it implies for your organisation. We also show how BACS can be smartly combined with an Energy Management System (EMS) to look beyond compliance alone.

What is BACS?

BACS stands for Building Automation and Control System. It is embedded in the European Energy Performance of Buildings Directive (EPBD) and has a clear purpose: buildings must not only measure energy use, but also actively control it.

A BACS must at least:

• monitor and store energy consumption;
• identify and report inefficiencies;
• control installations automatically;
• be interoperable: communicate with different systems according to EN ISO 52120.

In other words: BACS turns a building from passive to active energy management.

When does the obligation apply?

The rollout happens in two stages:

• 1 January 2026: mandatory for buildings with heating or cooling systems > 290 kW.
• 1 January 2030: mandatory for buildings with systems > 70 kW.

Sectors such as logistics, industry, retail and offices will often fall within scope. It is therefore wise to map out now whether your site needs to comply.

Why was BACS introduced?

The background is straightforward: the grid is becoming congested, energy prices are volatile and buildings account for a large share of overall consumption. With BACS, companies gain control of their installations and energy efficiency shifts from a nice-to-have to a mandatory part of operations.

For governments this means:

• lower CO₂ emissions;
• better utilisation of the electricity grid;
• less need for costly physical grid reinforcement.

For businesses this means:

• fewer unexpected costs;
• better insight into system performance;
• a direct link between regulation and day-to-day practice.

What does this mean in practice for companies?

A BACS is not a standalone device you can just add. It requires an integrated approach to energy management. Think about:

• an inventory of current systems (HVAC, lighting, shading);
• assessing whether a building management system is already in place;
• determining which upgrades are needed to meet the standard.

Important: a compliant BACS can replace mandatory EPBD inspections. That saves time, costs and administrative burden.

BACS versus EMS

Many organisations ask: will we need both a BACS and an EMS?

The answer is yes — they complement each other.

• BACS focuses on building-related functions: heating, cooling, ventilation, lighting, shading.
• EMS focuses on energy assets that interact with the grid: batteries, solar panels, EV chargers, CHP systems.

By connecting both systems, you prevent them from working against each other. Example: the BACS may want to cool in the afternoon, while the EMS wants to avoid a peak because of grid congestion. Integration ensures comfort and grid optimisation go hand in hand.

Practical example

Consider a distribution centre with 300 kW of cooling, solar panels and multiple EV chargers. From 2026, a BACS is mandatory to automatically monitor and control HVAC and lighting. But only with an EMS can this site also:

• avoid EV charging and cooling creating peaks at the same time;
• make smart use of self-generated solar power;
• stay within contracted grid limits.

The result: compliant with legislation, lower energy costs and a smaller CO₂ footprint.

How to prepare?

1. Check the size of your systems: do they exceed the 290 kW or 70 kW thresholds?
2. Map your building installations: is there already a BMS (Building Management System) that partly complies?
3. Think ahead: compliance is the baseline. The real value lies in combining BACS with EMS.
4. Plan integration early: this prevents duplicate investments or systems working at cross-purposes.

Conclusion

BACS will be a legal requirement from 2026. For many organisations it may feel like an extra burden, but it also creates opportunity: more control, lower costs and better preparation for the future. Do not see BACS as the end point, but as a foundation. With an EMS alongside it, you unlock the full potential of your building while staying compliant with ease.