When doing a new circuit or addition I detail exactly on the COC what work was done, number the fuses and quote that on the COC form.
I will tell the owner that there is old wiring which may require upgrading sooner or later and also write that on the COC.
( seen old wiring on other circuits and notified owner )
I have struck a couple of times that a new powerpoint was looped to older wiring and the rewirable fuse replaced with an MCB to avoid having to fit a ELCB.
Re fires - I find that a lot of people and businesses leave equipment always on standby or just switched on all the time, like computers.
The capacitors will age a lot faster and could cause a fire.
Also a lot of multiboards are used with these horrible plugpacks, some of them run quite hot to the touch. They are hidden behind a desk and often covered with all sorts of junk and can easily overheat and start a fire.
