Characters
‘Built by faith’, indeed! That simply means the workers weren’t paid properly.
— Mr. Emerson ‧ A Room with a View

Behind the line May contain spoilers.
Our reading
An editorial interpretation.
The speaker scoffs at the phrase "built by faith," reading it as a polite cover story. In his view it simply means the workers were underpaid. The remark is sceptical and sardonic, pointing to the labour behind grand buildings rather than the pious ideal attached to them.
Context reviewed