Summarises the results of medium and full-scale fire tests concerning shielded, sprinklered fires in high-rise office buildings. In particular discusses the effect of sprinkler system on heat release rate, compartment temperatures, carbon monoxide production and smoke generation and movement for fires in an open-plan office scenario. Also provides an initial analysis of the implications of a sprinkler system on a zoned smoke control system.KEYWORDS: year 1997, Offices, multistorey buildings, sprinklers, testing, carbon monoxide, smoke, fire