It is claimed that electrical equipment such as freezers, fridges, irons and washing machines which cut in and out can produce voltage spikes when the switches open and close. If two of these happen at the same time it could affect unprotected microprocessors. If there are lifts in the building these can produce quite large effects. Thunderstorms can send spikes down electrical supply wires, telephone lines and aerials but a surge protector may not cope with these - it is best to unplug equipment during electrical storms. So the answer is yes, fit a surge protector.