Sustainable Building Assessment System (BNB)

What is it?

The Bewertungssystem Nachhaltiges Bauen (BNB) is the German federal building ministry’s holistic assessment method for public construction projects. It assesses the ecological, sociocultural, economic, technical and process quality of a building across its whole life cycle. Current system variants cover office and administrative buildings, teaching buildings, laboratory buildings and outdoor facilities, and further variants are being developed and maintained by the BBSR on behalf of the ministry.

Methodologically the BNB is tightly linked to the ÖKOBAUDAT database, which is the binding data basis for the life cycle assessment. Both generic and company- or association-specific EPD data sets feed into it. The BNB has been established since 2010/2011, is developed continuously and complements the federal guideline on sustainable building. Alongside QNG it forms the second major public methodological axis for life cycle assessment in German construction.

Who is affected?

Directly addressed are the federal building administration and the clients of public building projects: schools and universities, administrative buildings, research institutions, armed forces sites and federal authorities. For those projects the BNB is the given methodology. Public building remains a stable source of demand across economic cycles.

Indirectly, but decisively in practice, manufacturers of construction products are affected whenever their products are used in public buildings. Their products feed into the building’s LCA and into its pollutant assessment. Anyone who wants to be specified in public construction cannot avoid the BNB: the LCA calculation necessarily draws on ÖKOBAUDAT, and the data sets held there determine the footprint of the final product, the building. Manufacturers without an ÖKOBAUDAT listing or without a product-specific EPD are calculated against generic values, with the assessment disadvantage that follows.

Which deadline applies?

The BNB has no single mandatory date. It has been established for more than 15 years and is maintained continuously. What matters for manufacturers is not regulatory cut-off dates but methodological update cycles.

• The BNB profiles and annexes are revised in regular iterations. The version currently in force is published on the BBSR’s BNB portal.
• The ÖKOBAUDAT data basis has moved to EN 15804+A2, and older A1 EPDs are increasingly excluded.
• EPDs are normally valid for five years. The update routine has to run on a rolling basis so data sets remain available in ÖKOBAUDAT.

Anyone who wants to stay active in the federal building market should treat the EPD data basis not as a one-off exercise but as continuous maintenance.

What has to be done?

For manufacturers with ambitions in public construction the programme is clear.

• Submit product-specific EPDs to ÖKOBAUDAT, company-specific or association-specific depending on product strategy and volume. Without an ÖKOBAUDAT entry your product is calculated against the generic data set for its category.
• Keep EN 15804+A2 current. The ÖKOBAUDAT data basis has moved to A2, and A1 holdings are losing their effect. Being A2-capable serves the BNB route directly.
• Show data depth. Clean modelling pays off in the BNB assessment, particularly for multi-layer construction products. Recycling and end-of-life assumptions have to be documented so they can be followed.
• Think about pollutant requirements too. The BNB assesses not only greenhouse gases but also pollutants, VOC emissions and service life assumptions. Keep data sheets and test reports ready for submission.
• Engage on specification. The best data basis in the world wins no contracts if the product does not appear in the bill of quantities. Become visible early in tenders, planning offices and BNB auditor networks.
• Think about QNG in parallel. If your data works for QNG, you effectively have the BNB route alongside it. The two systems are methodologically close.

What happens if you do not?

There are no direct sanctions, because the BNB is an assessment method rather than a legal act. But without product-specific EPDs in ÖKOBAUDAT your product is calculated against the generic data set for its category. In the BNB assessment that produces weaker results, and therefore a disadvantage against competitors who report their specific values.

Across the large federal building volumes, new schools, university expansion, new administrative buildings and research facilities, that effect has a measurable impact on specification share and supply opportunities. On top of that, the methodological data basis the BNB requires is increasingly expected in private construction and in certification-oriented projects as well (DGNB, QNG). Not being set up for the BNB builds a deficit on several levels at once.