Without Colour Management
With Alan's help, I have changed some of the lighting and have also tweaked the ambient occlusion node. It's looking a lot better than before, but I did run into a few little problems when rendering. When I had colour management turned on, it looks a bit washed out and grey, as you can see below, and so I kept colour management off. It is a bit darker and a bit more orange, but is a lot clearer compared to the other render.
I have made a camera that goes round in a circle, which is continuously focusing on the building and so I have left that to render. Once that is complete, I'll move on to trying the Wireframe turanaround tutorial.
With Colour Management