It used to be a large factory/warehouse, but its currently unnoccupied because the land is going to be sold off to build houses, until then the building that was the offices/security/reception its being rented out as a residential property to my bird and her mate, but their lease gives them access to the entire site, so the whole thing is legally class as one large residential address as that way squatters cant move in to the warehouse either.

Its actually relatively common for propertys to be protected this way.

Whole RAF bases, fire stations, railway stations, all manner of buildings which need to be empty for a couple of years while planning permission goes through etc without the risk of squatters moving but dont really need security guards there 24/7 to protect anything from theft as there is nothing there to steal anyway.