What lies beneath

We had to remove some rotting decking from the side of the house to access an electric cable - I say we buy the builders did it at my request. I had not realised that part of the structure was embedded in the wall render so now that it is gone, we have a gap through which we can see what is underneath the render on the extension. Interestingly it looks as if the structure is pretty good. Thought I would take a photo before it is covered over again.