Cottage, one of three in that area that have been occupied as long as I've known about them. Next time I go over I'll try to speak to the neighbours to see if they have the same.
This is inside the house. You go through front door into entrance area with three doors, living room to the left, bedroom to the right, with smaller bedroom in the middle. It's the small bedroom in the middle that has the concrete ceiling.
The comments about it being a shelter room are possible as I found a website with instructions. Needs more investigation so will have a structural survey done. I'm concerned as although we don't have many sizeable earthquakes I wouldn't like to be under it.
https://www.abomb1.org/pdf/sheltr03.pdf
It's a detached bungalow built in 1910 on the edge of a small town, two properrties beside it are similar so the obvious thing is to ask the owners. Only one a has sold over the last 50 years so there's not really been any need for structural surveys.
I'm thinking about buying a house and the home report references a concrete slab in the loft space. The house has living room and bedroom with an entrance area from front door and smalller bedroom between them. The concrete slab is above the smaller bedroom and looks to cover the whole space...