Intensive livestock farming is a major production system in Flemish agriculture, with nearly 6 million pigs and 28 million poultry units. Over the last five years, there’s a tendency towards fewer, but larger farms, resulting in about the same end production values. This evolution can pose both acute and long term problems in a region with a high population density like Flanders. The most recent odour research in Flanders is documented by Ghent University (De Bruyn et al., 2001; Van Langenhove and De Bruyn, 2001; Van Langenhove and Defoer, 2002). Since 2004, it became obligatory in Flanders to build low ammonia emission housing systems. Until now, the impact of this important evolution is not investigated with regard to indoor odour concentration and emission behavior. This lack of knowledge results today in a problematic situation for the livestock industry, whereby the exploitation of extensive animal farming can be hindered. Therefore, ILVO started some odour focused research projects in collaboration with Ghent University. In 2011, ILVO started with the development of an olfactometric measuring facility in order to generate up to date odour concentration and emission levels from animal houses in Flanders. The “Odour Lab” at ILVO is built to fully comply with the European and Belgian standard for olfactometry, CEN EN 13725 (2003) and NBN EN 13725 (2003). Since November 2011, the odour panel selection procedure was started. Up to now, from a test population of 43 candidates, 30 persons performed n-butanol tests on 3 nonconsecutive days. From these 30 persons, 11 persons were found qualified for both criteria of CEN; 16 persons failed for either one criterion and 3 persons failed for both criteria. So both criteria of the European Standard proved to be bottlenecks. It could also be concluded that sustaining a workable number of panel members, makes the panel selection procedure a continuous and dynamic process. A first sampling and measurement campaign was started in January 2012. Odour sampling was done in ...