Question

Is (built for )a phrasal verb

Answer 1

No, “built of” (or “be build of”) is not a phrasal verb according to most accepted definitions. The term “phrasal verb” usually indicates a small group of words, functioning as unit in a sentence, consisting of a verb modified by an adverb or preposition. But importantly it must have a meaning that cannot be derived from the separate meanings of its component words, and it is this that does not apply in your example. If you know what “built” means and “of” means then you immediately know what “built of” means. An example of a true phrasal verb is “fed up” - I might know what “fed” means and what “up” means, but that doesn’t really help. I have to learn the special meaning of the combination “fed up”.

Answer 2

Build In/Into is a separable phrasal verb and has 1 definition.

Definitions of Build In/Into:

1. To add a fixture or component to a certain area or place through construction.

Examples: People now build a security system into their homes for maximum protection.

I would love to have a vanity built in my bathroom.