BNB Evaluation Methodology

The actual assessment of the qualities of the building and the processes takes place at the level of the individual criteria, which are described in criteria profiles. These include descriptions of the individual criteria with objectives, relevance and evaluation methodology, the evaluation standard and, if necessary, explanatory annexes. The evaluation standard defines a target value (max. 100 points), reference value (50 points) and threshold value (10 points) for each profile, whereby at least compliance with the threshold value must always be demonstrated for certification.

The criteria profiles are thematically grouped into criteria groups and assigned to main criteria groups. Depending on the relevance of the individual criteria for the protection goals of sustainable construction, they are weighted within the main criteria group with a significance factor of 1 to 3 (low to high significance). The significance factors are predetermined by the respective system variants and cannot be adapted to specific projects.

The degree of fulfilment in the respective main criteria groups is calculated from the individual results of the criteria profiles. The fulfillment levels of the five groups are calculated taking into account the defined weightings to form an overall fulfillment level and the final score is determined from this. The grade - or degree of fulfilment - is used to assign the gold, silver or bronze quality standard. The location profile is assessed separately from the building qualities and is shown on the certificate as additional information. In the case of civil federal construction projects, at least the BNB’s "silver" quality standard must be achieved in the case of certification.

For different uses / system variants such as Office Buildings, Educational Buildings, Laboratory Buildings and Outdoor Facilities criteria have been developed and defined according to which an evaluation can be carried out. Certification is only possible if all criteria have been processed and the minimum requirements have been met.

At the beginning of the project, goals are set for the individual criteria, which are to be implemented in the planning and construction phase. By means of concepts and variant studies, the best possible solutions for the construction project are to be found, since the BNB criteria evaluate many different aspects that need to be examined with regard to their interactions. For completion, the objectives achieved are verified by means of the measurable and verifiable criteria.

A special feature of federal construction is the so-called "analogous application" of the BNB. This is intended for small construction projects (according to the current decree of the Ministry) or if the building cannot be assigned to an established BNB system variant - such as sports halls or partial renovations. In this case, the qualities described in the criteria profiles are individually checked for applicability at the beginning of the project and adjusted if necessary. The defined project objectives can then be checked against the criteria during planning and construction - as with the complete BNB application. Simplified “substitute procedures” have in some cases been published for the verification process.