Usually it's common area, otherwise muppets build on it and change it.
Op needs a committee, you must have a juristic person already. Probably at AGM they need to raise supplementary funds to pay for all railings to be fixed.
I wouldn't buy a condo with so few units
Update to the above.
Windmill 1 and Windmill 2 both open up and downstairs and both very good. Dollhouse closed, sold to Windmill, girls moved to Windmill 2, Dollhouse is being refurbished and will re-open as Windmill 3
i don't need it just yet, but was interested what it was in case it's worth trying in the future. If you want to try it now I'll tell you the location just outside of Pattaya
Apparently very effective, said the coffee shop lady, her mother takes it and feels brand new. 10 packets for 150 baht. Not much info on packet, i wondered what they were