height=1 doesn't seem right. https://www.openstreetmap.org/way/4960820/history 
We've got that and then roof:height=219 giving the actual tower height.

But what is 1 meter here? Is that height of the concrete base of the tower or something? It used to be building:height=1 (why?) and then this edit https://www.openstreetmap.org/changeset/115874568 has copied that 1 value overwriting the main height tag while getting rid of building:height . Was this a UK-wide automated tag tidying edit? Looks a bit like overwriting height as 1 was a mistake here, but I could be missing something.