Things must have been bad in London to make moving to what Ried's survey found in Sunderland
'Reid’s interest focussed on yards off the High Street in the east end. The 18 th century streets, from Church to Silver Street, were nine to ten metres wide, but nearby, and particularly in the yards of the medieval borough, were lanes and alleys narrower than three metres, and even, in the cases of Bull Lane (5ft 3in)and Moor Lane (6ft 6in), less than two. The inspector’s main concern was not with new cottages or houses, even where subdivided, but with the large dwellings, three or more storeys with cellars, accom modating six to 12 families.
Sunderland parish had 1,652 houses, in which lived 3,740 families, a population of 17,022averaging more than 10 per house and only 223 of the houses had lavatories.The situation was little better in Monkwearmouth and the Shore, and even Bishopwearmouth (which included the Panns) averaged seven people to a house, with a third of the properties housing more than one family.2
https://www.victoriacountyhistory.ac.uk/sites/default/files/work-in-progress/growth_1800-1914.pdf
