Hello
Regarding Chapels converted into dwellings, or other premises, with a Cemetery or Graveyard, or burial sites with no building.
I am fairly certain that under past PPG (Planning Policy Guidance), relating to History and Heritage and the current NPPF (National Planning Policy Framework), see also Historic England (formerly English Heritage) advice online, that as part of the Planning permission, all the memorials ought to be recorded in writing and ALSO photographed and ALSO referenced to a Plan, before work starts and it should be on the Planning file, many Councils have these files, or Plans going back over 100 years.
They are also required to keep Planning Files, so don't be fobbed off.
Any Memorial disturbed, covered etc., should have a permanent record made, this applies to floors, walls, graveyards and even where the building is not Listed, or there is no building anymore. Planning should have this info.
Email the Council Planning Dept currently responsible for Planning Applications where the Chapel stands, also email the Council's Planning Conservationist and also email the County Planning Archaeologist and HER (Historic Environment Record) you should find their contact emails online.
Mark