BNK/BNG – Assessment system for sustainable building

The BNK/BNG (QNG) certificate is a seal of quality for sustainable construction that distinguishes residential buildings in Germany. Since 01.01.2023, all residential building sizes can be certified: BNK (QNG) for buildings with 1 to 5 residential units and BNG (QNG) for buildings with more than 5 residential units.

The certification process runs parallel to the planning and construction of the building. A BNK/BNG auditor accompanies the project from the planning phase through to completion. Certification takes place in several stages:

1. Selection of a BNK/BNG auditor: These are BiRN-trained experts in sustainable building, such as architects, engineers or energy consultants. They provide support in the planning and implementation of sustainability goals.
2. Registration of the project with BiRN: The client registers the building for certification and concludes contracts with the auditor and the BiRN certification body.

Definition of sustainable planning objectives and documentation: Sustainable goals are defined together with the auditor and the necessary documentation is prepared. Once the construction is complete, BiRN checks the documentation and issues the certificate if the audit is successful.

We answer questions, advise and support you in the successful fulfillment of your BNK/BNG certification. Find out more about the assessment system in relation to the requirement criteria, the certification costs and the certification process.