Sorry Buildersmate that I obviously confused you. In explanation, LR helped us to find plans which were contained within the original Conveyance (hence the yellowed patchment). Each time a Title is transferred to a new owner, the Transfer Deed along with a description of the land and a revised plan of any changes to building or boundaries has also to be attached. We can witness in our documentation, the building changes made to our property over the years by comparing the old Conveyance with recent Deeds of Transfer. LR is a wonderful resource in situations where there are boundary disputes and would not be able to help unless they had this information to hand. As for planning permission, I am not so naive as to believe that all building alterations have been subjected to these strict procedures. LR together with Local Authority searches can confirm the presence of a DIY bodge.
I may have misunderstood Josie but if she is looking for comparisons of the size and shape of her property as they relate to changes made by previous occupiers, compared with the original build then I still feel that LR would be able to direct her as they did for us.
If Josie is only seeking plans of internal changes then I agree that LR would not hold these.