Strange question. Do you mean which building will withstand a direct lightning strike or which will suffer the least amount of damage after a devastating lightning strike?
I will try to answer both.
a) A lightning strike is normally directed to lightning rods and grounding which divert a strike directly to the ground. Therefore all properly constructed buildings behave the same.
b) In the event there is no lightning strike grounding, a wood building will behave as an insulator and will be unlikely to be struck. However if it is wet it could be disastrous.
c) If there is no grounding a steel building will conduct the hit through the structure itself, putting people and equipment at risk.
d) an ungrounded concrete building will be less likely to put people and equipment at risk.
In the rare circumstance that a fire develops from the lightning here are some things to consider when exposed to extreme heat:
I) wood burns
ii) steel melts
iii) concrete spalls
In a wood structure the amount of structural damage occurring is time dependant. A short term fire will create only minor structural damage and very localized.
In a steel structure a fire can be catastrophic. Entire buildings have fallen due to localized fires.
Concrete structures can be repaired relatively easily after a major fire.
So there is no easy answer but all are either best or worse. Best bet install and maintain an effective lightning rod system.
The best defense against lightning is a good lightning ground system, and such a system can be designed for any construction type, whether it be steel, concrete, masonry or wood. Having designed a few buildings in areas where electrical storms are a hazard, steel structures are the most straight forward because, along with designing the separate lighting ground system, the steel beams and columns are all grounded, along with a "Ufer" ground (grounding electrode in the concrete footings), adds additional protection from static discharge. Concrete construction is virtually as good, since the concrete is steel reinforced and, in a good grounding system, the reinforcing steel is indirectly connected to the building grounding electrode system.
Concrete. Steel will melt, wood will ignite.
Concrete and wood
