This chapter discusses the use of precision livestock farming (PLF) techniques to monitor the housing environment in intensive livestock production systems. It discusses the effects of variables such as temperature and humidity on animal productivity, health and welfare. It also shows how environmental conditions affect production of greenhouse gases such as methane (CH4) and nitrous oxide (N2O) as well as other damaging emissions such as ammonia (NH3), The chapter reviews ways of measuring and managing these environmental variables in dairy, poultry and pig production to make livestock production more sustainable.