Simple solution: find some ashes from a dead pig’s burned carcass, and sprinkle them on the building site once ground-breaking has occurred. Once the ashes have been irretrievably mixed with the soil at the building site, make that fact public. They’ll never be able to “uncontaminate” the site, and therefore will be unable to build.
I like your idea. How about a vat of pig fat dumped so it is right under the foundation. Or a trail of bacon grease all around the perimeter of the building. I think some really lewd Abercombie&Fitch billboards right next to the building may help too.