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N Mark for thermal insulation materials
N Mark of quality for thermal insulation materials

N Mark for thermal insulation materials

N Mark for thermal insulation materials

The N Mark for thermal insulation materials certifies the quality of extruded polystyrene insulation, expanded polystyrene insulation, on-site polyurethane applications, elastomeric insulation, mineral wool, EPS hollow bricks and panels and metal sandwich panels

AENOR product certification is accredited by the ENAC and is recognised in the General Register of quality standards of the Technical Building Code (CTE) by the Directorate-General for Architecture and the Housing Policy of the Ministry of Public Works and Transport

The products covered are:

  • Expanded polystyrene for building applications (UN​E-EN 13163) ​
  • Extruded polystyrene for building applications (UNE-EN 13164)
  • Rigid polyurethane foam systems for on-site application by spraying (UNE-EN 14315-1)
  • On-site application of rigid polyurethane foam (UNE-EN 14315-2)
  • Expanded polystyrene hollow bricks used together with precast concrete beams/joists for systems forged with joists and hollow bricks (UNE-EN 15037-4)
  • Hollow bricks and expanded polystyrene elements for grid slabs and uni-directional slabs concreted on site (UNE 53974)
  • Mineral wool for building applications (UNE-EN 13162)
  • Mineral wool for building equipment and industrial installations (UNE-EN 14303)
  • Elastomeric foam for building equipment and industrial installations (UNE-EN 14304)
  • Self-supporting double skin metal faced insulating panels (UNE-EN 14509)

As a compliance assessor, AENOR is a leading product certification entity. The AENOR N Mark now features on more than 100,000 certified products in more than 40 countries and is one of the world's five most popular quality marks.

The AENOR N Mark is a voluntary mark that allows the company to demonstrate that their product complies with certain provisions established in a UNE, EN or ISO standard, or in a technical specification. This proof of compliance, based on AENOR's rigorous monitoring of manufacturing processes and final product tests, will enable holders of the Mark to place products of a high quality and standard on the market, which will instil confidence in the users of certified products.

Royal Decree 314/2006, of 17 March, approving the Technical Building Code (CTE), is the regulatory framework that establishes the requirements that must be met by buildings in terms of basic safety and habitability aspects, established in Act 38/1999 of 5 November, on Building Standards (LOE).

The AENOR N Mark is recognised by the Ministry of Public Works and Transport as a CTE quality symbol. This recognition means that the Administration is sufficiently confident in the products certified under the AENOR N Mark considering that the use of these products in buildings contributes to compliance with the basic requirements set forth in legislation. For this reason, use of AENOR N Mark products benefits all agents involved in constructing a building.

This way, the AENOR N Mark can provide the following advantages:

The manufacturer

  • Better understanding of a product due to the exhaustive control the AENOR Mark establishes with respect to the same
  • Products that do not comply with relevant standards or regulations can be detected before they enter the market
  • Decreases production costs as a result of greater control during the manufacturing process
  • There are commercial grounds to introduce the product into new markets and facilitate access to works

Business providers and monitoring agents

  • Fewer or no checks upon delivery are required for goods provided for by the CTE
  • Ensures that products used in works comply with applicable regulatory requirements
  • Guarantee that the product has previously been verified in order to determine compliance with the minimum requirements of basic CTE documents

The end user

  • Properties are built using materials of proven quality
  • Products are certified by a well renowned entity that is a global leader in the certification of building products​​​


The AENOR Mark is voluntary. Companies that want AENOR to certify their product must submit their application in accordance with the formats established by AENOR. This application must include information about the company and the characteristics of the products for which certification is sought.

Once the documentation is analysed by AENOR technicians, the conformity assessment is initiated to verify that the products comply with the applicable standards:


A visit is made to the production centre to carry out the following procedures:

    • a) the quality management system is audited in accordance with the UNE-EN ISO 9001 requirements that are directly related to the production process.
    • b) The manufacturer's manufacturing process and production controls are inspected to ensure the product complies with the requirements of the standard.
    • c) ​ Samples are taken to send to an accredited laboratory, which performs the tests included in the standards. The manufacturer sends samples identified by the auditor to the laboratory.​


The laboratory performs the tests established by the standard and sends its report to AENOR.


Using all the information on the activities performed, the Technical Certification Committee (independent body comprising all the interested parties: manufacturers, the Administration, users, monitoring entities and AENOR) will either propose to AENOR that the Mark be granted, or request that one of the activities be repeated due to non-compliance.

Once the certificate has been granted, the process continues with the follow-up activities required to maintain it. Samples will be taken, and audits, inspections and tests will be performed on an annual basis. A Technical Certification Committee assesses the result each year, deciding on whether the Mark can be upheld.

Once the certification process has been completed, organisations obtain: ​

  • The AENOR product certificate
  • A licence to use AENOR's Mark of certified products
AENOR N Mark logo for a certified product

Certified product sheet: Thermal insulation for construction​​​

Virtual technical seminars: AENOR certification for thermal insulation materials​​

Installation of products

SI Mark for Installation Services

​​​The SI Mark certifies the performance quality of organisations that install products on-site

GlobalEPD Declarations

Environmental product declarations (EPD)

​​​​AENOR manages the GlobalEPD Programme of verification, in accordance with Standards ISO 14025 and ​EN 15804

European Passport

​​The CE MARK is a passport for building products

The CE mark provides access to the European Economic Area for construction products


Keymark European Mark

​The voluntary CEN Mark to demonstrate compliance with European standards