OP here... yes HOA is for a Condo (20 units in 2 apartment buildings). Assessment is for siding. I'm almost sure it will end up being more than this. A couple years ago when we replaced the roofs a $90,000 roof job turned into a $200,000+ job to fix some rotting chimneys.
On this siding job. The estimate is only like $200,000 for the actual siding and more than 100% more for "overhead" like state sales tax, permits, architect, inspector, etc.
So our $310 dues were just enough to cover insurance, water, sewage, garbage, outside manager, yardkeeping, and usually 1-2 emergencies per year (leaky pipes, water damage, etc). There was very left over to build reserves, thus the need for the big assessment and dues increase.