BNK/BNG – Certification

BNK and BNG are rating systems for sustainable residential buildings in Germany. As of January 1, 2023, residential buildings of all sizes can be certified: Buildings with 1 to 5 residential units are certified using the Sustainable Small-Scale Residential Construction Rating System (BNK), and buildings with more than 5 residential units are certified using the Sustainable Buildings Rating System (BNG).

A BNK/BNG auditor oversees a project for certification from the planning phase through completion. The auditor may also serve as the project’s architect or energy consultant (who has completed additional training to become a BNK/BNG auditor). Alternatively, the auditor may be involved in the planning and construction process as a separate auditor.

How does the BNK/BNG certification process work?

1. Selection of a BNK/BNG Auditor
2. Defining Sustainability Goals and Implementation Strategies
3. Registration of the Project with BiRN
4. Documentation of the Measures Implemented
5. Review of the Documentation by BiRN
6. Awarding of the BNK/BNG Seal of Quality

The BNG/BNK certificate is one of the accreditations required to obtain the QNG and, consequently, to qualify for the “Climate-Friendly New Construction” grant program with the QNG. After a successful conformity assessment by BiRN and the issuance of the BNK/BNG seal of approval and the QNG, these documents can be submitted to KfW to apply for funding for climate-friendly new construction.