BNK/BNG certification

BNK and BNG are assessment systems for sustainable residential buildings in Germany. Since 01.01.2023, all residential building sizes can be certified: Buildings with 1 to 5 residential units with the Assessment System for Small Sustainable Housing (BNK) and buildings with more than 5 residential units with the Assessment System for Sustainable Buildings (BNG).

The BNK/BNG certification system assesses the sustainability of residential buildings on the basis of specific criteria, which are set out in so-called criteria profiles. These criteria cover various quality areas in order to ensure a comprehensive assessment of sustainability: Socio-cultural quality and functionality, economic quality, ecological quality and process quality. The BNG/BNK certificate is one of the awards that are a prerequisite for obtaining the QNG and thus also for the promotion of climate-friendly new construction with QNG.

A BNK/BNG auditor accompanies a project for certification from the planning phase through to completion. The auditor can also be the architect or the energy consultant (with further training as a BNK/BNG auditor) for the project. Alternatively, the auditor can be involved in the planning and construction process as a separate auditor.

How does BNK/BNG certification work?

1. Selection of a BNK/BNG auditor
2. Definition of sustainability goals and implementation options
3. Registration of the project with BiRN
4. Documentation of the measures implemented
5. Review of the documentation by the BiRN
6. Issue of the BNK/BNG seal of approval

The BNG/BNK certificate is one of the awards that are a prerequisite for obtaining the QNG and thus also for the promotion of climate-friendly new construction with QNG. After successful conformity testing by the BiRN and issuance of the BNK/BNG seal of approval and the QNG, these can be submitted to the KfW in order to apply for the Climate-Friendly New Construction grant.