In message , soup
writes
popped their head over the parapet saw what was
going on and said
Have now decided the smell is coming from the walls which were re-
emulsioned about a month ago probably with standard emulsion over
previous coating of "emulsion for bathrooms".

Any other suggestions of sources of smell

Only thing I can think off is (a) dead rodent(s) in the wall.
Never heard of emulsion off gassing for over a month.


Sounds likely

--
Richard Faulkner