Overpass query to select buildings in hamilton county not recently edited.

old-building-query.txt

[timeout:600];

// Hamilton County area by id
rel(104784); map_to_area->.ham;
// get older buildings inside the county 
way(area.ham)[building](if: timestamp() < "2014-08-25")->.buildings;

// iterate over buildings, checking the dates on their nodes
foreach .buildings->.way {
  // only add ways to the result set if nodes are also 
  // not recently modified
  node(w.way)(if: timestamp() > "2014-08-25");
  if (count(nodes) == 0) {
    ( .way; .result; )->.result;
  }
}
// recurse to include nodes of ways
(.result;>;); 
out body;