You must live in a warm climate or sprinklers in residential attics could really get messy.
The difference between OH1 and OH2 typically doesn't amount to a hill of beans on a project as long as you aren't fighting an extremely poor water supply.
I wish local people wouldn't make amendments to the standards. A short while back a friend of a friend contractor was building a restaurant of about 45 sq. ft.. All wood construction, wood trusses, plywood roof deck, everything combustible. While the state building code didn't require sprinklers the owner wanted sprinklers and since the architecturals, reflecting a non-sprinklered building, were completed he didn't take any sprinkler trade offs. I gave a price of $18K (sprinklers above and below) starting 1' AFF.
Figured 4" run-in, double check in the mechanical room with FDC on the building, Local fire offical rejected the drawings wanting 8" tap, 6" into the building, a new hydrant located at the pit where the FDC would be located.
All fine and good, I agree with the fire chief this is better protection, but the owner freaked over the additional $30K sprinkler system underground part of the project.
Owner stopped the sprinkler installation, paid us for our time to date and opened a non-sprinkled restaurant five months later.
