Hi - I just wanted to canvas some opinions on the provision of fire hydrants. Approved Doc B seems to imply that a single hydrant is sufficient irrespective of a buildings size/ required percentage of vehicular access. No reference, in terms of hydrants is made to BS 9990 however it seems appropriate that a designer would refer to this is establishing their proposal. BS 9990 under section 5.2 states that where hydrants are provided as part of a fire ring main system and that these be provided at not more than 90 meter centers. A fire ring main system is defined under 3.10.3 as '..water main which encircles a building or series of buildings ...'. So, AD-B = hydrant, BS 9990 ring main with hydrant outlets at 90 meter intervals.