This is Terminus House in Harlow. Built originally around 1975 and designed by Principal Architect J C Whitney of the Harlow Development Corporation this office block ran into hard times and became unoccupied for a long time in the 2000’s and was converted into 214 flats as reported by the press, 222 according to the developers (including the painting over of the original concrete) under the controversial Permitted Development Rights (PDR) scheme in April 2018
It would be reasonable to suggest that the conversion was not a great success. “It’s like an open prison” according to this piece in The Guardian.
According to this BBC article the ex-office block provides “human warehouse’ housing”
This Essex Live article suggests Harlow Terminus House is “The ‘nightmare’ tower block where London boroughs are dumping leftover residents”
The following video covers exactly why PDR is such a bad scheme and covers specifically the problems with Terminus House in its new guise.