How to punctuate rhetorical sentences?

I would do it this way:

I'd use:

When building a new plant, the guiding motivator should be how we create a great business, not how we build big projects.

Just one thing Val, it says the question is building the plant. You might say instead, "In the building of a new plant…."

Otherwise I like Jes' and Punks' above

You don't need all the commas and you aren't quoting anyone.

Inverted commas are used in direct speech , not reported speech.

When building a new plant the guiding question should be how do we create a great business, not how do we build big projects.

http://www.oxforddictionaries.com/words/punctuation-in-direct-speech

Yea Vet, the trend is away from the comma

Dale do you understand that there is no quotation in the sentence being discussed?

Yes Vet but why do you ask, pray