We've just got the survey back on a 1900 house we are in the process of purchasing.

Ceilings
originally lathe and plaster (much remains). Some rooms tacked over with plasterboard and tapped, but not plaster skimmed (poor finish).

Front room ceiling-lathe and plaster lost key in one corner of the front reception room
Other rooms- polystyrene tiles onto likely lathe and plaster which may be disturbed if removed.

Walls
Internal lathe and plaster, papered and painted. One of the suggestions is in the course of improvements
to remove the lathe and plaster, and replace with insulated backed plasterboard to enhance thermal efficiency (no cavity wall construction).

Some plaster applied directly to walls is rough, uneven and may need to be re-skimmed.

So it seems a big job. We are planning to get a re-wire done.

Is possible to review the condition of the lathe and plaster before paper removal ? It's not clear wether this lathe and plaster is serviceable

If in doubt, board over it and skim he board. Creates less mess and gives thick sound absorbing ceilings. Expect to pay up to £ 300 per room plus decorating