With the entry into force of Regulation (EU) 2024/3110, known as the Construction Products Regulation (CPR), the concept of the harmonised zone becomes a key element for understanding when and under which conditions a construction product must comply with common European rules.

The harmonised zone includes all products for which at least one European harmonised technical specification, known as hTS – harmonised Technical Specification, is available.

When a product falls within this scope, European technical legislation becomes mandatory and establishes, in a uniform manner across all Member States:
 

• applicable requirements and corresponding test methods;

• performance assessment criteria;

• the content of the Declaration of Performance;

• rules for affixing the CE marking.
  
  

In practical terms, if a product belongs to the harmonised zone, it may be placed on the European market only if it complies with the applicable harmonised standard. This is not an optional choice for the manufacturer, but a legal obligation under the CPR.

Implications for manufacturers and Member States

The inclusion of a product in the harmonised zone has direct consequences for both manufacturers and national authorities. Member States may not impose additional or different requirements compared to those already defined by harmonised European standards.

Additional tests, national markings or alternative technical specifications are therefore not permitted: compliance with the harmonised standard and correct CE marking are sufficient.

This mechanism underpins the free movement of construction products within the EU single market. A compliant product can be marketed in all Member States without the need to adapt to different national requirements, thereby reducing technical barriers and avoiding duplication of costs.

Why the harmonised zone is central to the new CPR

Regulation (EU) 2024/3110 introduces a broader and more modern concept of construction product, in line with technological developments in the sector. The definition now also covers:
 

• kits and systems;

• prefabricated elements;

• products manufactured using 3D printing;

• reused or recycled products.

This approach reflects both innovation trends and the needs of the circular economy.

In this framework, harmonised standards and the harmonised zone become the key instruments for ensuring a consistent European approach in terms of safety, performance, sustainability, durability and emissions.

Given the wide diversity of the construction products sector – ranging from bricks and insulation materials to complex systems and innovative materials – the harmonised zone ensures regulatory consistency, traceability and free circulation of compliant products throughout the European Union.

What happens outside the harmonised zone?

When no harmonised standard exists for a specific product category, the product is considered “non-harmonised”.

In such cases, manufacturers may still place the product on the market, but the CE marking obligations laid down by the CPR for harmonised products do not apply. Member States may therefore introduce national requirements, conditions of use, additional certifications or other rules, provided they are compatible with the internal market.

Products not covered by hTS and voluntary CE marking

Where no harmonised technical specification (hTS) exists, the manufacturer is not required to apply a harmonised standard and is therefore not obliged to request a conformity assessment based on an hTS. However, an alternative route is available.

The manufacturer may:
 

• request a European Technical Assessment (ETA) through a Technical Assessment Body (TAB);

• once the ETA is obtained, draw up the Declaration of Performance and Conformity (DoPC);

• affix the CE marking.

In this way, a product not covered by an hTS may circulate freely within the EU market, under the same conditions as other CE-marked products.