Dilapidated is an adjective describing something (usually a building) that's run down and falling apart.
With most usages, dilapidated is not same as devastated.
in this context coud I replace "delapidated" with "devastated" : One of the buildings he bought was dilapidated, however over years he had rebuilt it.
You could change it to --
One of the buildings he bought had been devastated; however over years he had rebuilt it.
Also, note the semicolon instead of a comma.
ok, thank you for your help :)