This comment made me curious: I was under the impression that planning permission focused on the impact that works would have on the surrounding area, and that planning permission would therefore be invalidated if the design of something substantially changed in a way that would impact the local environment, or other nearby properties.
But the platform arrangement at Whitechapel is presumably entirely underground, so whatever the arrangement ends up as, you'd have expected that will have no significant impact above ground. I'm therefore curious as to how that might invalidate planning permission. Is there something about planning permission that I have misunderstood?
Whitechapel District line platforms are open-air.