Hi im just wondering which regs addition to apply i have a domestic dwelling to check the electrics and add some minor works and also inspect and test. The additions are coming off excisiting circuits and the installation is 15th/16th addition. On inspection the DB is an old wylex with rewire fuses and the bonding is in 6mm. So do i take it i am obliged to upgrade the fuse board to one with mcbs and the bonding to 10mm or do i do the work to the 16th addition and put down on the PIR a recommendation that it be upgraded, i mean how far do you go with it obviousley its not up to 17th addition so you couldnt apply those regs as the circuits arnt wired that way for starters. The owners are letting the property out so they need the cert. I have had several different answers from different electricians. I did my 2381 2391 2382 and cant remember anything mentioned about this type of situation. So do i upgrade the part of the house that is 15th to the 16th and upgrade the db and bonding and do i test to the 15th and 16th as there are two different insatllations confused.com spike