Calling lenders about ADU income turns up four answers and four different haircuts

For a buyer trying to qualify with projected income from an accessory unit on a one unit purchase, the agency rule allowing it existing does not mean the shop on the other end of the phone will actually apply it. Calling a wide set of lenders on this question tends to produce a predictable split: a handful say yes and can point to the underwriting page, a few say yes on the phone and go quiet when asked for the matrix in writing, worth treating as a no, and the rest do not count it at all. Among the real yeses, terms differ meaningfully. Some require the accessory unit to be legal and permitted on the county record before any income counts. Others will work from an appraiser's rent schedule with the unit as is. Haircuts on the appraised rent commonly run from 75 to 85 percent, with some lenders unwilling to commit to a number until they see the property. Nearly all apply a cap limiting how much of total qualifying income can come from that unit. A fully underwritten pre-approval built this way, rather than a letter off a soft credit pull, can move a workable purchase price by tens of thousands of dollars in a market where that is the difference between houses with a rentable space and houses without one. Terms move and overlays change constantly, so anyone doing this should get their own lender's current rules in writing rather than relying on someone else's search. The question worth ending every call with: send me the page.