Pressurization is the only smoke control system that is acceptable to be used to discount a stair provision in Approved Document B and can be used to replace almost any prescribed solution for protecting staircases, for example Natural AOV's, Natural Shaft Systems or Mechanical Shafts systems, often known as MSVS. BS 9991 is currently being updated, but is likely to recommend pressurization for single stair residential building up to 30m, the alternative being two stair systems. Pressurization has been around for many years and is regarded as being the best possible smoke control strategy to keep stairs clear of smoke so why hasn't it been more popular? This presentation will discuss this and outline the requirements for pressurization systems, their limitations and what implications and benefits they can bring when introduced into building design.