Which Vs Where in RC

1- Houses where a lot of natural light comes in are better for you.

I have read a lot about this topic and come across two rules:

1)

If the place we are talking about is the subject or direct object of the relative clause, then use which or that.

Let's try this:

The relative clause would be:

(A lot of natural light comes in houses) = NOT a Subject NOR an Object

2)

A) If the relative (pronoun / adverb) is replacing:

A noun e.g. The house, use which (The house which I live in is small) RC = ( I live in THE HOUSE)

B) If the relative (pronoun / adverb) is replacing:

A prepositional phrase PP e.g. in the house, use where (The house Where I live is small) RC = ( I live IN THE HOUSE

Keeping these two rules in mind, how would you explain 1 ?

Houses where a lot of natural light comes in are better for you.