Aircraft hangar detection

[Messy]

Aircraft hangar detection:

A medium size hangar has flame detection only. I am investigating replacing it (or augmenting it) with either VESDA or beam detection to speed up detection, but cannot find much in the way of guidance other than a US related NFPA document and a document relating to MoD standards.

Has anyone here much experience with such premises?

I would appreciate a steer in the right direction

Video smoke detection is not an option. Been there, tried that for another large building - it was useless