Clem Ziroli Jr.’s mortgage firm, which has seen its costs soar to comply with new regulations, used to make about three loans a day. This year Ziroli said he’s lucky if one gets done.

His First Mortgage Corp., which mostly loans to borrowers with lower FICO credit scores and thick, complicated files, must devote triple the time to ensure paperwork conforms to rules created after the housing crash. To ease the burden, Ziroli hired three executives a few months ago to also focus on lending to safe borrowers with simpler applications.