Back in August 2019, a friend and I noticed the option of staying in university dorms in London during the summer holidays.
We picked Imperial College, which is located near the South Kensington tube station and the Victoria and Albert Museum and within easy walking distance to other Kensington attractions.
These were dorm rooms, single rooms with the bare essentials, including a full private bath, but no air conditioning. The price was £392 for four nights for each room, including VAT, not bad for central London. No meals were included, but the night we arrived, my companion and I had a simple dinner in the campus restaurant/pub that was across the quadrangle, and after that, we took advantage of the many restaurants and cafes in the area. There was also a convenience store on campus. Everything was spotlessly clean.
Two downsides: The elevator closest to our rooms was broken and was not repaired during our stay. We had to take the elevator in the adjoining building and walk down halls and through fire doors to reach our rooms.
The other was that we were just coming off a week-long choir residence in Canterbury, and I chose this particular accommodation because I would be going on to do some extensive touring in the British Isles while my companion would be leaving at the end of the stay in London, so I was attracted to the promise of laundry facilities. Alas, using the laundry facilities required downloading three different phone apps, and then my phone didn't work in the sub basement where the machines were located.
When I checked out, I mentioned on the evaluation form that it would be nice to have an alternative to the phone apps, maybe a washer/dryer or two that could be paid for with coins or a card.
Other than that, I wouldn't mind staying there again, although I would not assume that I could wash clothes.