Why do we say "all the building", but not "all the room"?

Question

I'm doing the exercises on Hewings' book: Advanced Grammar in Use and came across this problem that I have. Anyway, first, let me quote the explanation in the book.

Before singular countable nouns we usually use the whole rather than all the:

• They weren't able to stay for the whole concert. (rather than ... for all the concert.)

There are two questions that make me think and re-read this explanation:

Underline the more appropriate answer. If both are possible, underline both.

6. The new heating system makes (all the building / the whole building) warmer.

7. (All the room / The whole room) was full of books.

The key answer gives me: both are possible for number six, but the answer for number seven is only "the whole room". As explained in the example above that I can use either of them (although the whole is preferable), why all the room is incorrect? The book should have added the option if it were correct. I have looked up and both building and room are singular countable nouns if it matters.

Answer 1

I would think that buildings can be referred to as countable objects when the number of rooms or levels is considered. In this particular case, we might mean that all the levels of the buldings get warmer or all the rooms in the building get warmer. This can't be applied to the example about the room.

Answer 2

Whole means complete, entire.

Have you read the whole book?= Have you read all the book?

I spent the whole winter in London.= I spent all the winter in London.

The new heating system makes the whole building warmer.= The new heating system makes all the building warmer.

Most often we use whole with a singular noun. Whole is more common than 'all' with singular nouns.

The whole room was full of books. or All the rooms (of the building) were full of books. (NOT 'All the room was full of books.')