Quorum is the number of members who must be present in order to call a meeting to order and to transact any business at a meeting. Quorum doesn’t change according to the type of meeting, or whether or not a special resolution is on the agenda.
Quorum varies from co-op to co-op, so you will need to check your Rule 14.13 ‘Requirement for quorum’. This Rule will tell you how many members entitled to vote must be present at the start of a general meeting, as well as how many members entitled to vote need to be present at all times after the start (usually a lesser number).