hi, i am about to replace a friends upvc french doors for a set of new ones, ordered the door from a FENSA registered upvc company so the new unit will be o.k, the 'old' upvc units in the house are not covered by FENSA, as im changing like for like and the new unit is FENSA, will that be o.k or will i need to get a council inspector round to give it a certificate, got to start it monday if poss so any info would be most welcome