Small Multifamily: How Lenders Add Up Rent Across Units

A DSCR loan for a multifamily property is underwritten the same way as a loan on a single family rental: the rent has to cover the payment. The only real change is that the rent arrives from several leases, and the lender adds them up before dividing. Up to four units, that math is routine. At five units the file changes shape. And small cheap buildings hit a wall that has nothing to do with the ratio: a DSCR loan minimum loan amount the purchase price cannot reach.

Which buildings qualify at all is covered in the property types a DSCR loan can be used for. This page handles the part the single family examples skip: combined rent, vacancy on a small multi, and the loan size floors and limits that decide whether a duplex is financeable.

How lenders total rent across units

Gross rent for the property is the sum of the units. A duplex where each side pays $2,000 produces $4,000 a month, the same income as the site’s standard $500,000 rental renting for $4,000. A fourplex at $1,000 a door produces that same $4,000.

Work the standard example through. A $500,000 purchase with 25% down at 7.5% gives principal and interest of $2,622 a month. Add $6,000 a year of property taxes and $2,500 of insurance, which is $708 a month, and PITIA is $3,330. Rent of $4,000 against $3,330 is a DSCR of about 1.20, whether that rent came in as one check or four. On the calculator’s simple tab, where you enter the payment yourself, $4,000 of rent against a $3,200 payment reads 1.25.

So unit count does not change the arithmetic. It changes the paperwork. Each occupied unit needs its own signed lease, and the appraisal for two to four units is Form 1025, which carries rent comparables unit by unit rather than a separate single family rent schedule. If you want the detail on how that income figure gets set, how the appraiser’s rent schedule works covers it.

Duplex to fourplex: the residential ceiling

One to four units is residential for lending purposes. That ceiling is why a fourplex is an easy DSCR file and a five unit building is not. You get residential appraisal forms, residential rate sheets and the same qualification logic as a house.

Two things to confirm with your loan officer. Many lenders price two to four units a little above a single family rental, and some ask for a slightly lower maximum LTV. The size of that add is set by the lender’s rate sheet, not by any rule, so get it in writing before you pick a program.

House hacking is the other trap. DSCR loans are investment property loans, so moving into one side of a duplex usually breaks the terms. The answer to whether you can live in a property financed this way applies to a unit in your own building too.

Five units and up: a different loan file

At five units the building is commercial property in the eyes of a lender. The deal may still be sized on a debt service coverage ratio, but almost everything around it moves: a commercial appraisal built on the income approach, an operating statement for the building, a term that is often five or ten years with a balloon rather than a 30 year fixed, an entity on title, and larger reserves. Mixed use buildings with ground floor retail land in the same bucket.

Most programs that market themselves as DSCR loans stop at four units. If your plan is three duplexes rather than one six unit building, you stay inside the easier program the whole way.

Loan size floors that knock out cheap doors

Why the floor exists

An appraisal, title work, legal review and underwriting cost roughly the same on a $90,000 duplex as on a $500,000 one. The interest on a small loan does not cover that. So lenders set a minimum loan amount, commonly somewhere between about $75,000 and $150,000 depending on the program. There is no industry number here, and the figure moves with the lender’s cost structure, so treat any range as a starting question. The site’s answer on the minimum size a DSCR loan can be goes into the thresholds themselves.

The effect catches buyers in low price markets. A duplex at $90,000 with both sides rented can carry a payment three times over and still get declined, because the loan is too small to write.

Limits at the top end

DSCR loans are not agency loans, so agency conforming limits are not what binds. Each lender publishes its own maximum per property, and most also cap total exposure to one borrower, either in dollars or in number of loans. Ask for the floor and the ceiling in the same conversation.

Blanket loans versus one loan per property

A blanket loan is a single loan secured by several properties. The lender pools the rent, pools the payments and underwrites one ratio. For cheap doors it is often the only route, because four $90,000 duplexes together clear a minimum that none of them clears alone. You also pay one set of closing costs instead of four.

The cost is flexibility. The properties are cross-collateralized, so selling one requires a release clause and the lender’s sign off. A prepayment penalty applies to the whole balance, not the one door you want out of. Refinancing a single property out of the pool is awkward. The quiet advantage runs the other way: one vacancy gets absorbed by the rent from the rest of the group, which is exactly what a single property loan cannot do.

Vacancy and management on a small multi

Many DSCR lenders qualify on gross rent with no deduction for vacancy or management, since taxes, insurance and HOA already sit inside PITIA. Practice varies by lender, and some programs do apply a vacancy factor. Either way, run your own version. A fourplex has four turnovers to absorb, and management on small buildings is commonly quoted at 8% to 10% of collected rent, higher for fewer units, and set by your local market. The treatment of each of these line items is laid out in what actually goes into the ratio.

Partly vacant buildings: what to enter in the calculator

Say three units of a fourplex are leased at $1,000 and the fourth is empty. If your lender counts leased units only, enter $3,000 of rent. Against the $3,330 payment from the example above, that is a DSCR of about 0.90, below the point where the rent covers the debt. If the lender accepts the appraiser’s market rent on the vacant unit, enter $4,000 and the ratio returns to about 1.20.

That single underwriting choice is worth 30 basis points of coverage on a small building. Run both figures, then ask which rule the program uses.

Run your building

Put the combined rent from every unit in the rent field of the DSCR Loan Calculator on the home page, then enter the price, taxes and insurance for the whole building. Run it a second time with the vacant unit at zero to see where the file sits if the lender counts leases only.