no but you do need an engineers stamp along with the architect's seal to submit for building permit. standard operating procedure for any construction non-singlefamily-residential over 4000 sq ft

is the condo in some sort of co-op situation...
i've heard of people having to submit their plans
or at least their intent to renovate to their condo boards
for approval...is this what you're talking about...as far as
a stamp i don't know..but maybe just some sort of letter of
approval or the like?

archiphreak: that depends on what state you're in. An engineer's stamp is only required here if the building exceeds 3 stories or 15,000 square feet (so you could build quite a lot of condos with no engineer's stamp.)
yoiyoi: I've never heard of a "condo certification" - is this some local requirement - i.e. the type of thing that requires a design review by some sort of board to be "certified?"

condo certification means it goes to comittee to be approved... just like landlord approval