> 1. Our house floor was sparkling clean.
> 
> 2. Our house's floor was sparkling clean.
>
> 3. The floor of our house was sparkling clean.

The three examples above are all grammatical. However, they are not all as natural as each other. The first is the least natural. Sentence (2) is more likely, but still not very natural. The third would be the most likely sentence. The reason is that when the "owner" of the thing is not animate, we tend to prefer to use "the X of Y". If it's animate, we tend to prefer "Y's X":


 - The colour of the bottle (the bottle isn't animate)
 - Bob's leg (Bob is animate)

This is not a grammar rule, but it is what native speakers tend to do. So if want a natural sounding sentence, it is safest to go with option (3) here.

Whether or not to use a compound noun is a bit more difficult to predict. I don't know of any good guide to how acceptable a compound will be in any given instance. It's probably best to see if you can find other examples before you put a compound like that into any essay, for example. The "X of Y" construction will nearly always produce acceptable results when "Y" is not animate. So it doesn't really matter if you use this when there is a well-established compound also available:

 - The door of the car ...
 - The car door ...

Both of the options above are perfectly natural.