My office is a bit lightning prone, so I was thinking about putting our backup server in a separate building in case we get hit. However, the other building is only about 30-40 metres away, on the other side of a car park. Is that likely to be good enough, or would it be a waste of time?

Anyone have an idea how big an area gets fried during a lightning strike?

In thailand it's difficult to say, since it all depends what piece of electrical equipment blows out where. It could be locally in the building in which case 40m is fine, it could be the local transformer, which also could be fine, but there is a chance that it will effect both buildings. Lastly there are the bigger electrical substations around bangkok, those do get hit, not that often but if they do, it's a bit of a mess.

To be honest the building next to you should be fine in most cases, unless you run mission critical apps on it that require >5n uptime. Then again, if you did have those requirements your servers would be in a datacenter and not in an office somewhere.

Hmmm...I think the transformer is in the carpark in between both buildings. Maybe I'll just have to arrange some kind of separate portable backup that I can take home from work as 'insurance'.

Not sure if it's possible, but every where I've lived I've had a lightening/ground rod (sai din). Would it be possible to get one put in?