Finishing Basements

Has anyone here finished their basement?

I'm considering finishing ours, but to finish the ceiling I'd need to raise the sprinkler pipes slightly, point the sprinkler heads downward, and (since I don't want to catch my head on them) replace the bulb heads with flat or low-profile ones. I imagine making changes to the sprinkler system will involve permits, inspections, approvals, some scheduling, etc, so I'm curious if anyone has already gone through it.

Thanks,

Colin