Homologation Documents (DH)

Background

The creation of mechanisms to assess the quality of new construction in Portugal dates back to 1951 with the publication of the General Regulations for Urban Buildings (RGEU). Article 17 of the RGEU stipulated that the application of new materials or construction processes for which there were no official specifications or sufficient practice in use would be subject to the prior opinion of the Civil Engineering Laboratory.

From 1963 onwards, these opinions were translated into a Homologation Document (DH). To this day, LNEC has issued more than 900 DHs, covering a wide range of construction products and systems.

The homologation of construction products and systems is currently the subject of a new legal framework as a result of the technical harmonisation of construction products in the European Union. 

Consequences of European harmonisation

Over the last few decades, the European Union has promoted an extensive set of far-reaching technical harmonisation actions aimed at eliminating technical barriers to the free movement of construction products.

It began with the publication, in 1989, of the Construction Products Directive (CPD), which was repealed by the Construction Products Regulation (CPR) - Regulation (EU) No 305/2011 of the European Parliament and of the Council of 9 March 2011 - in force since 1 July 2013.

The CPR obliges the affixing of the CE marking to a construction product when it is placed on the market, provided that it is covered by a harmonised European standard or complies with a European Technical Assessment issued for that product.

As a result of this harmonisation, the body of European and national legislation on construction products has grown significantly, leading LNEC to stop issuing DH for several construction products that are now covered by the standards published in the meantime. 

Legal framework

The definition of the scope of LNEC's homologation was included in Decree-Law no. 50/2008, which amended Article 17 of the RGEU.

According to the legislation currently in force, construction products and systems used in urban buildings must be subject to LNEC homologation if:

• are not covered by Portuguese Standards or European Standards adopted in Portugal;
• are not subject to a European Technical Assessment;
• are not subject to mandatory certification, as is currently the case with steel for reinforced concrete reinforcement (Decree-Law no. 390/2007) and for prestressed concrete reinforcement (Decree-Law no. 28/2007).

However, homologation is waived if certain conditions referred to in Article 17(5) of the RGEU, as amended by Decree-Law 50/2008, are met. 

Contents of a DH

A DH for a construction product or system includes, in addition to the Approval Decision, a general description of the product or system in question, a list of its characteristics, the field of application, rules for application on site, an overall assessment with an indication of the foreseeable service life (determined based on the results of the tests carried out and observations resulting from visits to manufacturing facilities, works in progress and constructions in use) and the characteristics and respective tolerances to be assessed when carrying out any acceptance tests.

DH with Certification

In addition to issuing simple approvals, LNEC also grants certified approvals to products whose production is subject to permanent internal control by the manufacturer and external control by LNEC (or an entity recognised by it as competent for this purpose); this external control includes periodic visits to the manufacturing facilities to check production conditions and the procedures adopted in that internal control, and the collection of samples for testing at LNEC.

Confirmation of an approval issued in another country

For foreign construction products or systems that have been homologated in their country of origin and provided that the respective homologating institute is a member of the European Union for Technical Approval in Construction (UEAtc), LNEC can carry out a homologation confirmation study, which, if favourable, will lead to the issue of a DH.

This study will consist of verifying that the on-site application procedures set out in the foreign approval are suitable for works carried out in Portugal and are being followed in our country, verifying any additional requirements of a national nature and, as a rule, carrying out identification tests using material collected from the manufacturer's representative in Portugal to confirm that the product or system being imported corresponds to that approved in the country of origin.

Validity period

A simple Approval Document is usually valid for three years, after which it may be revised at the request of the manufacturer and renewed if the results of the re-examination carried out by LNEC are satisfactory. This re-examination includes carrying out new tests and verifying the conditions of manufacture and application, as well as reassessing their suitability for use.

Certified DHs are issued with a validity period of five years and can be renewed if the manufacturer requests it, following a simplified set of procedures carried out by LNEC.

On the other hand, the validity period of HDs corresponding to confirmations of foreign approvals is usually linked to that of the original approval and expires when the latter expires.

Preliminary assessment

In the case of construction products and systems that are subject to homologation, but whose commercialisation in Portugal is still at an incipient stage or whose industrial development does not yet allow for the granting of homologation, it is considered that the issuing by LNEC of a favourable opinion, usually translated into a preliminary assessment, is the appropriate way to comply with the provisions of the aforementioned legal diploma. However, once the above conditions are no longer met, those products or systems must be approved.

If you would like more information about DH, please send an e-mail to: lnec@lnec.pt