The taxi drives out of the city, through the suburbs and deep into a sprawling estate that has a cluster of high-rise flats in the middle, which tower over the grey concrete houses below. In places you cannot tell where the roofs end and the sky begins as the clouds swell and gather on the horizon. At Sandra’s block I buzz the ‘concierge’ button and a Jamaican Geordie opens the door, smiling to reveal half a dozen gold teeth and explaining that Sandra has been called to a meeting at her son’s school but will be back soon. He phones one of her neighbours and Barbara, a nervous, twitchy woman in her fifties, comes down to collect me and take me to wait at her flat. She leads the way through a concrete stairwell that smells of fresh paint and urine, up the stairs, out onto an exposed walkway and into her smoke-filled flat, where two young women are sitting on the sofa with their coats on. Barbara introduces me – “she’s come all the way from London just to talk to Sandra about her leccy” – and they joke about how they would all like a personal visit from their electricity providers so that they could ask for a discount, and they talk about the upcoming community Santa parade that helps to take the edge off the winter.

For the next few minutes, the front door opens and shuts, opens and shuts, as people drift in and out of the flat and Barbara explains that half the block has keys – it is like a second home to them, they share everything. Then Sandra comes in, beaming and bouncy, and Barbara hands me over. We hurry across to Sandra’s flat, her son Bailey leading the way on his bike, Sandra and I talking about the cold and the clouds, Sandra checking that I did not tell any of her neighbours why I am really there.

As soon as we are through the front door, Sandra ushers Bailey into the living room where his older sister is playing on the iPad, and tells them both to stay there until we have finished.