Death Takes A Trip — Gillian Larkin

Julia Blake runs her own cleaning business. She has the unfortunate knack of getting herself involved in murder investigations.

When one of Julia's elderly clients, Douglas Pedley, is found dead at the bottom of his stairs, it is soon obvious that he was murdered.
Julia first suspects the building contractors who have been hounding Douglas to sell his land and property. It's not long before another suspect appears.
Julia is determined to find out who murdered the old man.