Ok, Ok, I looked up the laws.
Neighbor, you can read the laws in RCW 64.34. The Bellingham Public Library has the RCWs in the reference section. You can also read the laws & research caselaw at the county courthouse law library (basement, open 'till 1 or 2 every day). Don't forget to read the pocket parts.
I don't know much about condos, so I didn't follow some of your terms. A condo association {CA} is responsible for any repairs/maintenance to 'the common elements'. 64.34.328. Your assessments have to be based on a budget adopted by the CA Board. 64.34.360. Assessments that benefit only some condos or were neessitated by one owner's actions can't be assessed against everyone. Id. Read the certificate line by line to ensure the CA apportioned the expenses correctly.
The CA can impose & collect assessments and set the budgetary revenues, reserves, & expenditures each year. 64.34.304(b). If the budget provides for a $50,000 reserve & the CA has a $200,000 reserve, I doubt the CA can assess more charges. It has to use the reserves. The bylaws should address this. If you aren't satisfied with what you find in the bylaws, you can work up a petition for a special meeting to address whether the Board has to use the reserves to pay whatever expenses they're trying to get you to pay. "Special meetings of the association may be called by ... unit owners having twenty percent or any lower percentage specified in the declaration or bylaws of the votes in the association." 64.34.332. You can always change the bylaws to make the board do what you want!
I couldn't find any law stating the required notification regarding assessment amount & due date. As a general rule, the CA should not be able to charge you late fees or interest until it has given you notice of the assessment amount & due date & a reasonable opportunity to pay. Read the CA bylaws & budget to see what they say about notice.
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This is not legal advice and you are not my client. Double check everything with your own attorney and your state's laws.