Hello,
I went to look at a house that has an interior basement wall built with blue lightweight concrete that is plastered, but through a hole it was possible to clearly distinguish the blue lightweight concrete. However, it was not possible to discern the size of the blocks.
The exterior basement walls are also built with a size that is unusual to me and I am trying to find similar dimensions on Google. I don't think it was possible to determine if it is blue lightweight concrete in these walls without drilling/scratching, which I assume isn't entirely OK to do during a viewing, so I refrained
Anyway, the blocks are, according to my assessment, sized LxHxD = 800-1000 x 200 x 250 (mm). The blue lightweight concrete blocks I find pictures of do not exceed 400mm in length, so that was why I had some hope that the exterior walls are built with something else; an interior wall is manageable, albeit a bit cumbersome with props, etc. during replacement, but the entire basement foundation is too much work.
Does anyone feel they have knowledge of dimensions of different types of wall blocks from that time? =) Added two pictures as the cracks in the joints make it easy to distinguish the size of the blocks with the windows as a reference.