Building odour emissions constitute an important contributor to the level of nuisance caused by a pig farm. Those emissions are less intense than what is produced by manure spreading, but their frequency and duration are much higher. The nature and concentration of more that 160 compounds affect odour characteristics of an air sample collected in a swine building. Considering this complex mix of substances, the human nose is still the best instrument to characterize odours. The forced choice dynamic olfactometry method is the most accepted technique used to measure odour concentration and intensity. It requires a meticulous selection of panel members, expensive equipment and an experienced panel leader. Different techniques have been discussed to reduce odour emissions from swine buildings. Even if a lot of research has been done, many questions stay unanswered. For example, more information is required on performance and impact on odour before new building designs, feed and slurry additives and biofilters can be recommended and applied on a large-scale basis. However, if the barn is kept very clean, the manure is removed as often as possible, an efficient dust control technique is implemented and multiphase feeding programs are used (to reduce nitrogen excretions), odour emissions from the building are likely to be maintained at an acceptable level for the average farm community.