Back up and don't confuse the man. All this talk about FD60 doors and intumescent strips. He's doing a terraced house so worst it would even be is an FD20 [so FD30]and as it'a single family occupancy he doesn't need intumescent strips.
The fire officer shouldn't add any additional requirements to fire doors other than those already noted in the ADs. The need for intumescent seals on a lot of doors ie Premdor and Jeld-Wen are because in the small print they are not deemed fire resistaive unless with fitted with the approriate seals.
I agree with Flatfish that he should install what he wants. A 35/40mm standard door will do fine. If you want better acoustics then put in a set of batwing seals or something as that will be better and cheaper.