I seem to be an ungracious lone voice about this book. I did read it all (and in my dotage I have at last decided it is permissible not to finish something I am not enjoying!)
I found it very worrying as I read it, and then came to the Acknowledgement at the end, where the author thanks all the patients she worked with in the mental health field. There seemed to be no one in the book who was not suffering from some mental health problem, and I was concerned whether we were supposed to find them funny, annoying, strange, or what?
At a practical level, yes, the large size of the book was unusual and made it a bit of a handful, but the larger typeface it allowed it to use was a relief after most paperbacks. I agree with the poster who suggested including a map of the Avenue with the names of the people who lived in the houses. That would help a lot.
Stylistically I found the use of so many complicated linguistic 'tricks' rather trying, like consuming a box of chocolates at one sitting, and also confusing when Grace, a 10 year-old, used the same style of language as the narrator.
I was curious about why the summer of 1976 attracted the author, and what research she had to do to describe the continuing heat.