Look both ways before entering

This bird obviously has a nest above the soffit of our house. We have seen it enter there several times at betweem 7.30 - 8.3opm. So today I set up the camera at around 6.30pm and waited (with food to pass the time).

Just before 8pm, the bird suddenly appeared, looked around to make sure the coast was clear, and then squeezed into the tiny gap between the soffit and the wall. An hour and a half wait, and 5 seconds of rapid shooting.

I've really no idea how it manages to get through that gap; I remember finding it difficult to get an electrical cable through there for an outside light.

Now the question - what is the bird? It looks like a very scruffy blue tit, but can anyone confirm?