The quality of the Masterbloc stacking block is demonstrated by different certificates awarded by highly-regarded quality institutes and inspection authorities both locally and abroad.


KOMO acts as an independent control body investigating and guaranteeing the quality of building products and processes.

Open certificate

The Masterbloc is the only stacking block on the market with a valid KOMO product certificate. KOMO has certified not only the stacking block, but also an entire wall made of Masterbloc stacking blocks.

KOMO also has a KOMO attestation plus product certificate, which combines the benefits of both a KOMO product certificate and KOMO attestation.

Players in the building and installation sectors increasingly recognise the added value of KOMO and its quality control. That is why the number of products with a KOMO attestation plus product certificate is growing by the day. Products holding a KOMO attestation with product certificate must at least display the KOMO quality mark and the certificate number.

The choice of attestation plus product certificate means you gain certainty about the product specifications. This certainty is guaranteed by an external expert who continuously checks whether the building product, building element or building system complies with the relevant regulations and legislation. This does of course depend on the processing instructions (if any) and application agreed in the prerequisites in the attestation.

KOMO provides a number of different services related to product and process investigation and certification, and awards the following certificates:

  • KOMO product certificate
  • KOMO attestation
  • KOMO process certificate
  • KOMO management system certificate.


The DIBt (German Institute for Building technology) is the only institute issuing certificates which authorise innovative and unregulated technical products and construction methods. The institute checks whether products comply with the building decrees in different German regions.

Open certificate

Masterbloc has received the DIBt “Zulassung” (approval) (number Z-17.1.-1146) for both its individual blocks and a wall consisting of Masterbloc elements. In addition to this “Zulassung” the Masterbloc system is also approved as a fire wall.

Before being able to award the “allgemeine bauaufsichtliche Zulassung“ (general technical authorisation) for a building product or building method, all important aspects of the product are inspected to confirm that they satisfy the relevant rules and regulations, with particular attention to safety characteristics and impact.

This includes:

  • Stability
  • Protection from harmful influences
  • Health protection
  • Protection from fire, heat, noise and sudden shocks
  • Traffic and transport safety


Kiwa is an independent certification organisation based in Belgium and the Netherlands focused on guaranteeing the quality of products and processes.

Open BB certificate

Open BSB certificate

Masterbloc has received a certificate from the Dutch ministries of Traffic and Water Management and VROM (number K23375/01) declaring that the Masterbloc system complies with the Building Materials decree.

KIWA starts with inspections, approvals and tests, based on which certificates are issued. Kiwa also operates as a technical centre for knowledge, research and training. Kiwa not only focuses on the building industry, but also carries out technical research for clients in many sectors, including the government, utilities sector and industry.

Kiwa’s aim is to promote trust in the quality of products and processes by making these transparent and providing guarantees, by specifically applying the technical knowledge they have acquired. In doing so, Kiwa have gained a good international reputation as a trusted certification authority.

The most famous example of Kiwa’s work is the Kiwa quality mark, which can often be found on the bottom of a product. This label (and associated certificate) offers immediate visibility of the inherent quality and reliability of your product.

The NL-BSB certificate provides a specific guarantee to the end user that the concrete products used are made from pure granulates, which can be traced back to the source, and that the water/cement factor has been respected (important in frost resistance). The independent and accredited certification institution KIWA checks several times a year whether the manufacturer is producing the concrete in accordance with legislation.


WTCB stands for “Wetenschappelijk and Technisch Centrum voor het Bouwbedrijf” (Scientific and Technical Centre for the Building Industry). This is a Belgian private research institution whose main task is to carry out scientific and technical research within the Belgian building industry. It also provides technical support and advice to encourage innovation in the building industry. WTCB’s services also include technical inspections, standardisations and certifications.

Before launching any new Masterbloc product on the market, we take advantage of the knowledge acquired at the WTCB to make a thorough check of our new product in terms of all relevant engineering properties. We do this of our own accord and pay for this service, without being legally required to do so, purely because we have a quality tradition and a mission to offer our customers only the best possible building materials.


CE stands for Conformité Européenne (European Conformity) and refers to compliance with European law. In practical terms CE is not a European label, but an indication that the product in question satisfies all relevant European regulations and complies with the appropriate guidelines that have been established by the European Union.

Masterbloc has received a compliance certificate (number 0620-CPR-90475/04) from Kiwa, as an independent approval department, for the production process of this product. Masterbloc has also received a certificate from Kiwa (number 0620-CPD-41438) for the compliance of our production process.

By using the CE logo the producer makes a public declaration that the product satisfies the strict European quality standards and accepts liability for the quality of its product. Therefore, the CE logo attached to our products guarantees that we produce the end products according to European regulations in terms of quality, performance and conformity.

For most building products it is mandatory to apply a CE mark as well as establish additional compliance/performance declarations, before being able to launch a product on the internal European market.


CE 2+ label was created to encompass the national labels Benor (Belgium) and KOMO (the Netherlands). This is because the need for quality extends beyond national borders. In a nutshell, CE2+ is the improved internal quality guarantee at European level.

With the CE 2+ mark we demonstrate that every step in the production process in our production facilities is controlled by an external agency (KIWA).


BENOR is a well-known and recognised Belgian quality label providing certainty that the  building products supplied have undergone a thorough internal quality control, under the supervision of an independent, external certification organisation.

Benor is owned by the NBN (Bureau for Standardisation), responsible for developing and selling standards in Belgium. The BENOR label demonstrates that a product or service respects a technical quality reference framework that has been approved by all parties concerned in launching it on the market. After approval this reference framework is integrated in a normative document, known as ‘Prescriptions Techniques – Technische Voorschriften (PTV)’.