A small flurry of last-minute amendments — some of them apparently pushed at the request of builder and Realtor groups — means it may take a little time for everyone to sort out all the details of those changes to the preservation ordinance city council passed earlier today. But here are a few highlights, as we’ve pieced them together: Creating a new historic district will now require the approval of owners of 67 percent of all tracts in the district. Also, decisions by the archaeological and historical commission (the HAHC) will now have more teeth: Property owners whose plans for renovations, new construction, or demolition have been rejected will no longer be able simply to wait 90 days and proceed anyway. However, HAHC rulings can now be appealed to the planning commission, and if that doesn’t work, to city council as well.

But the ordinance’s most exciting feature is the one-time opportunity for all existing historic districts — except for the Old Sixth Ward and Main St./Market Square — to remove the shackles of . . . uh, history. All it’ll take to start the repeal process in one of those districts is signatures of owners of 10 percent of the tracts. (And once the city posts the new petitions, districts will have 30 days to gather them.) For each district where that threshold is reached, there’ll be public meetings and a vote — by mail-in ballot. If owners of 51 percent of the tracts in a district vote for repeal, the planning director will recommend to city council that that district’s historic designation be removed — or that the boundaries be shrunk and redrawn to maintain 67 percent support. For each district, city council will make a final decision.

• Previously on Swamplot: Preservation Ordinance Passes