When I worked abroad we had a couple of loungers in the ops room so one of us could get 40 winks during the night when there was no local traffic. However, there was the threat of dismissal should we be found out.
When I went to Heathrow in the very early 70s there were communal dormitories for male ATCO, femal ATCO, male ATCA and female ATCAs. These were later changed to individual bedrooms with beds and a small bedside unit. Sheets and pillow cases were provided. When we moved to West Drayton in the early 90s we had to scrabble around to find an empty office in which to to rest. I would add that some offices were provided with folding beds. I don't know what the situation is at Swanwick.