These builds will not be done on a certain day, they will be held weekly or monthly. After the week/month is over, there will be a voting "booth" at the creative spawn. Along with these "booths," there will be a warp sign to that designated plot. Of course there is no way of knowing if someone votes for themselves so that can be what it is. At the end of the voting, which will also have a time span of a week,(monthly competitions will only be 3 weeks.) the drawings will be collected by staff and the reward will be given appropriately.
Commands.(small but useful only, such as /feed for survival commands[limited time only]) Survival rewards, such as money and/or items. Exclusive winner plots.(exclusive to winners, and completely separate from every other plot) Etc. As of right now, there are not that many reward ideas flowing through my head, but of course, over time this thread will be updated.