The Guides are in 2 parts with Part 1 written similarly to the Employers Guide. Part 2 shows more technical information and is based on the current Building regulations, although some part take on board some of the changes to be inserted in the new version!! Simple premises will not have to look further than part 1 whereas more difficult ones may have to look at, and the important DCLG phrase, dip into part 2. Like them or loathe them they will be the only guidance that can be utilised for existing buidings. It will be difficult to justify the use of a design guide like ADB or BS5588 for a FRA of an existing building where the Government have produced specific guidance for particular premises types. When you read them all though, other then some of the travel distance bits they all state the same stuff as we would expect. Occupanct, horizontal travel and vertical travel as protective safety and FA, FFE and other bits as preventive safety so FRA's follow the same trends as ever, providing everyone can do them of course.