How did the new Standard come about?

Work on the 9th edition of the Standard began back in 2018, when Wolfgang Maes and his newly formed ten-member SBM Standard Committee of experienced building biology professionals met for a day in Neuss. The committee of experienced building biology professionals, led by Wolfgang Maes, discussed the key features of the new edition and developed initial ideas. Because of Wolfgang Maes’ death in August 2019, further work on the SBM was put on hold for some time. At the end of 2021, however, Baubiologie Maes, the Institute of Building Biology + Sustainability IBN and the SBM Standard Committee resumed the work again.

The original idea was that no major changes were necessary, as the Standard had proven itself and was easy to apply. But when ten people sit down together and thoroughly go through each Standard point word by word, when everyone contributes their practical experience with building biology testing and the latest scientific findings are examined, when other experts are consulted, when so many things are discussed and debated until optimal solutions are reached and everyone is satisfied, it simply takes quite some time. And in the end, we gained many new insights. Both various subtle distinctions were clarified and some completely new paragraphs and guideline values were added, which was not expected at the beginning.

Starting in 2022, the SBM Standard Committee held monthly online meetings lasting around two hours for over two years. Research and consultations supplemented this process in between meetings in coordination with Baubiologie Maes and the IBN. So finally, in August 2024, the team completed and released a new edition, exactly five years after Wolfgang Maes’ death and 32 years after the publication of the first SBM in 1992.

What remains unchanged?

As changes were made, everyone involved considered it vital to stay true to the basic ideas of the Standard, which Wolfgang Maes had conceived and cultivated for years. We should mention the following key ideas here:

• Commitment to the holistic and comprehensive framework of three main categories:
• A – Physical Factors: Fields, Waves and Radiation,
• B – Chemical Factors: Indoor Toxins, Pollutants, Indoor Climate,
• C – (Micro)biological Factors: Fungi, Bacteria, Allergens;
• Special focus on long-term exposure (especially in sleeping areas);
• Pragmatic approach to identifying sources of building biology anomalies;
• Use of professional testing methods and procedures based on science;
• With the goal to create indoor environments that are as unpolluted, low risk or near natural as possible and to minimize risk factors within an individual’s framework of feasibility with a focus on what is achievable. The Evaluation Guidelines, for example, emphasize the one overarching guiding principle even more than before (found above the guideline value definitions and tables): “Any risk reduction is worth it. Guideline values are meant as a guide. Nature is the ultimate standard.”

What’s new?

The current Standard is not a revolution, but rather a careful development and refinement. In the Standard of Building Biology Testing Methods, which summarizes all risk factors in indoor environments relevant to building biology assessments and their causes, only a few updates and additions were made, such as highly debated PFAS were added to the pollutant list at Standard Point B3, and air electricity was moved from Standard Point B6 “Indoor Climate” to Standard Point A4 “Static Electric Fields.” The Testing Conditions, Instructions and Additions, and the Guiding Principles underwent only minor revisions. The existing specifications and explanations for most of the standard points in the Evaluation Guidelines, which is unquestionably the most important Standard document in the daily work of a building biology testing specialist, were still regarded as correct and sufficient, and only slight adjustments were made to the content in most cases. Here are a few examples:

• The preface and definitions of exposure ranges (anomalies) underwent slight adjustments in the Evaluation Guidelines.
• All paragraphs at the end of each Standard point, which provide information on other exposure limits, guidelines and assessment tools, were updated.
• The guideline values for radon now include the local background concentration level.
• At Standard Point B2, more detailed information about solvents and volatile air pollutants was added.
• The final considerations now conclude with a paragraph on the use of various measuring instruments and testing methods: “In many cases, exploratory testing methods can be used. However, when dealing with complex exposure levels or issues, it is advisable to choose more precise (and more sophisticated) testing equipment and methods.

A major and important change is that entirely new guideline values and assessment tools were developed for three Standard points: sound, light and odors. For the first time, they are easy to access and apply through the Evaluation Guidelines. The Testing Conditions previously contained only a few recommendations for sound and light.  

• For sound, Standard Point A8, previous recommendations in the Testing Conditions have now been expanded and introduced as guideline values in the Evaluation Guidelines. These values are based on our testing experience and case histories in the last years. The overarching principle “There should be no individual noises or vibrations that are perceived as disturbing” is now combined with guideline values for weighted sound exposure levels, specifically dB(A), dB(C), and dB(Z).
• For light, Standard Point A9, the few recommendations, which were first included in the Testing Conditions in the last 2015 SBM update, have now been expanded and included in the Evaluation Guidelines for sleeping areas. The guiding recommendations largely remained the same besides the addition of a few numerical values regarding illumination levels at night, color rendering index and flicker percentage of light sources.
• All the information about odors (integrated into Standard Point B6 “Indoor climate”) is entirely new. Understanding this issue is often challenging when it comes to objective testing methods. Experience, however, has shown that odors are responsible for roughly half of all inquiries about pollutants. Here, too, the overarching principle “There should be no individual odors that are perceived as disturbing” is supplemented with qualitative indicators of interpretation, instead of numerical guideline values, to assess the subjectively perceived odor intensity, pleasantness (how unpleasant is the odor?) and tolerance (how acceptable is the odor?).

Finally, we would also like to point out that, for AC electric and magnetic fields (Standard Points A1 and A2), new factors were developed for assessing frequencies higher than the usual power line frequency of 50 or 60 Hertz and predominant harmonics (among others, “dirty power”). And for the assessment of molds (Standard Point C1), besides previous guiding principles, there are now guideline values for the area’s size of mold growth and qualitative indicators for interpreting fungal parts as seen under a microscope. In addition, a critical threshold level has now been specified for the water activity in materials, which is an essential ingredient in mold growth.

Outlook

All in all, Baubiologie Maes, the Institute of Building Biology + Sustainability IBN and the SBM Standard Committee hope that the latest updates to the Building Biology Standard, together with its Guideline Values, Testing Conditions and Guiding Principles, will continue to make it a solid and even better tool than before for all building biology professionals and also for all those affected by indoor environmental problems. This will help us achieve our goal of ensuring that indoor environments and sleeping areas can be free of indoor pollution based on the precautionary principle.