The only people who can give a definitive answer are the local planners.
A long while ago the NatWest bank in Romsey needed its roof repaired but because it is a grade 1 listed (?) building all repairs had to be identical to the original construction even though better methods were available. I think in that case it was a matter of iron ties cased in lead that were holding the blocks together. These had to be replaced like for like despite the fact that they were going to rust again.