Indoor air quality in buildings: what does the law require today?

Air quality is receiving more and more attention. Rightly so, because indoor air has a direct impact on health, comfort and performance. Legislation is following this trend. The requirements are becoming clearer and stricter. Anyone working with buildings will notice this immediately.

Why air quality matters

People spend most of their time indoors. In spaces with poor ventilation, complaints quickly arise:

• Fatigue
• Loss of concentration
• Headaches or irritation

In environments such as schools, offices and care institutions the risks rise even further. Good air quality is therefore not an extra. It is a basic requirement.

What does the law say?

The regulations on ventilation and indoor air quality have been significantly tightened in recent years. The core is simple: sufficient ventilation, low CO₂ levels and visible monitoring.

1. Ventilation requirements (general guideline for public and collective buildings)

Most sectors today fall back on the same basic standards:

• A minimum of 25–40 m³/h per person, depending on the function of the space
• Education: approximately 25 m³/h per person
• Offices: approximately 40 m³/h per person
• Care institutions: 30–40 m³/h per person (depending on the type of space)

Recommended values are higher, around 50–60 m³/h per person for optimal air quality.

2. CO₂ standards (federal Indoor Air Quality Act – 2023)

These standards apply to all publicly accessible and collective buildings, including schools, offices, hospitality, fitness centres, care institutions, youth facilities, etc.

• Target value: ≤ 900 ppm
• Maximum allowed: ≤ 1200 ppm
• > 1200 ppm: action required
• > 1500 ppm: unhealthy situation

3. Monitoring and transparency

The law increasingly demands visibility and follow-up:

• CO₂ meters must be visibly placed in spaces where people stay for long periods
• Registration of measurements
• Action plan required when limits are exceeded
• Maintenance and balancing must be demonstrable

Enforcement is increasing, especially in public and collective buildings.

Where does it often go wrong?

In practice, the problem rarely arises from one big mistake. It lies in small links. Think of:

• Ventilation systems that are not properly adjusted
• A lack of measurements or follow-up
• Maintenance that does not happen

The result is the same: air quality remains below standard.

Expectations are changing

Users expect more than they used to. There is a need for:

• Transparency through measurements
• Certainty about the operation of systems
• Attention to health and comfort

Air quality is increasingly becoming a criterion in choices around buildings.

What works in practice?

A good approach starts early and does not stop after acceptance. Concrete actions:

• Take ventilation into account from the design phase
• Adjust and balance installations correctly
• Provide regular maintenance

This keeps air quality at the right level — also in the long term.

Questions or need support?

Feel free to ask your further questions to property manager SEBAS, we are happy to help. welkom@mysebas.be

Source: Juvah