my neighbor wants to extend her deck, which will impinge on my privacy. can i take legal action if the home owner association board approves project?

Unfortunatley there isn't really an easy yes or no answer to this question without knowing a bit more. If your association does approve the project the first question would be to ask whether the association properly followed existing artchitectual guidlines for your association when they gave their approval. You would also want to look at whether the association has ever approved or denied similar applicaitions in the past.  Thanks,Jon