To be clear, this is not a planning application in the conventional sense, but a “prior approval” application. This follows changes to change of use in recent years which mean that office to residential conversions no longer need full planning permission. The borough can only consider transport/highways, contamination, flooding and noise impacts when determining these applications - they can’t ask for any kind of section 106 contribution and can’t apply development plan policies outside of these areas. Prior approval is simply an officer determination so it won’t go to planning committee.
I am not at all surprised that this is happening to Heron House as it is exactly the kind of dowdy (but well connected) office block that the government was thinking of in making the changes.