The obvious repitition is more of a concern to me that the building entrance thing. As I go through each section, I will now look at varying the roof styles to break that up. So thanks for pointing it out.
When I first made the layout, a long time ago, I didn't put a huge amount of thought into it. Which is why I wanted to revist it and improve it.
As for the 'no entrance' thing...is that really such an issue. The rooms inside the middle section can be accessed via internal corridors. There is no reason why that section can't be an extension of a building with street access.
Edit: After looking at older cities on Google Earth I have noticed that although there are some instances of buildings as I have them, it is actually much more common to have a courtyard or open air walkway. So I guess I will replace some of those locked in buildings with courtyards.