After forwarding residents' concerns on to the City Council, here is the response, posted here by way of an update.  This is the latest reply as at 02/10/2017.

Click on the image below to download it.

Once any application has been made to the Local Planning Authority, Constituents can submit their concerns via Public Access, the Council's development control email account:

[email protected] or by post to the Local Planning Authority (LPA), Economy and Place Directorate at the Civic Centre, Burdon Road in Sunderland, SR2 7DN.