DSCR Loan for a Fourplex (4-Unit Property)

A fourplex is the ceiling. Four units is the largest property you can finance with a residential DSCR loan, and that single fact shapes everything about the deal. Cross into a fifth unit and you leave the residential world entirely — the loan becomes commercial, the terms change, and the cost of capital climbs. So a fourplex sits in a sweet spot: maximum rental income inside the friendliest underwriting box the DSCR market offers.

The test is the same one that governs every DSCR loan. The underwriter is not asking about your job, your tax returns, or your debt-to-income ratio. It is asking one question: does the combined rent cover the loan?

How the four-unit math works

DSCR stands for Debt-Service Coverage Ratio, and on a fourplex it’s the same fraction it always is — you just stack four rent rolls on top instead of one.

DSCR = combined unit rent ÷ the building’s full carrying cost

That carrying cost — what underwriters call PITIA — bundles the note payment with property taxes, hazard coverage, and any HOA or association dues. Picture four tenants whose leases add up to a combined gross rent, set against a fully-loaded monthly carry that’s roughly four-fifths of that rent figure. Divide the two and you land at a coverage ratio near 1.27 — the property generates about 27% more income than it takes to hold. Underwriters generally look for a ratio of 1.00 at minimum, while the sharpest pricing shows up in the 1.20–1.25 band, so a deal like that clears comfortably.

This is why the 2-4 unit class produces the strongest cash-flow per dollar invested. One mortgage, one set of taxes, one insurance policy, one roof — divided across four income streams. The fixed costs of ownership get spread thin, and the combined coverage tends to be the healthiest of any residential property type.

One nuance worth internalizing: the DSCR the underwriter uses is built on qualifying rent, not necessarily the rent your tenants pay today. On a fourplex the appraiser fills out a rent schedule for each unit, and the lender takes the lower of in-place rent and appraised market rent for the coverage calculation. That cuts both ways. If a unit is rented under market on an old lease, the appraised figure can lift your DSCR above what the current rent roll suggests. If a unit is rented over market — say a tenant who’s been there a decade on a sweetheart deal that the next tenant won’t pay — the appraisal pulls the qualifying number down to the comp-supported level. Underwrite the building on appraised market rent and you’ll rarely be surprised at the closing table.

Why four is the wall

The line between residential and commercial is not a soft preference; it’s a hard convention baked into how the entire lending system is built. One-to-four-unit properties are classified as residential. They use residential appraisal forms, residential DSCR programs, and residential pricing. Five units and up are commercial — full stop.

That distinction is worth real money. Residential DSCR loans give you 30-year fixed amortization, no balloon, a simple gross-rent coverage test, and the deepest pool of competing lenders. The fourplex captures all of that while running the maximum number of doors the residential rules allow. It’s the last and largest rung before the ladder switches to a different building.

The four-unit cap is also why so many investors treat the fourplex as a deliberate destination rather than a stepping stone. You can scale a portfolio of four-unit buildings indefinitely, each one financed on clean residential terms, without ever touching commercial paper. Four fourplexes is sixteen doors underwritten the easy way; one sixteen-unit building is a commercial deal with all the friction that comes with it. The residential rules reward you for keeping each asset at or below the line, and the DSCR test makes that scaling almost mechanical — every building stands on its own rent, so adding the next one doesn’t depend on your personal income or how many properties you already hold.

What you’ll bring to a fourplex deal

Plan on slightly heavier requirements than a single-family or duplex, because lenders price four units as marginally more complex:

• Down payment of 25% is the common starting point. A strong ratio with high credit can occasionally see 20–25%, but budget for 25% on a four-unit purchase.
• A credit score of 660+, with meaningful pricing breaks at 700 and 720.
• Reserves run higher — figure 6 to 12 months of PITIA. More doors means more potential vacancy, and underwriters want a deeper cushion on a fourplex than they’d ask for on a single unit.
• An appraisal with a rent schedule (Form 1025, the small-residential-income form, plus Form 1007 rent comps per unit). The appraiser’s market-rent figures set the DSCR — not the current leases, though strong in-place rents help.

You’ll almost always close in an entity. Titling a four-unit building in an LLC is standard practice for liability and bookkeeping reasons, and DSCR lenders expect it. If you’re working out the structure, our guide to closing a DSCR loan in an LLC walks through how the entity holds title without changing the underwriting.

What happens the moment you hit five units

Cross into a fifth unit and the deal is a different animal. A five-plus building is underwritten as commercial DSCR, and the changes are substantive:

• Terms shorten. Thirty-year fixed gives way to structures like 5- or 10-year terms with balloons, or longer amortizations priced as commercial paper.
• The underwriter stops looking at simple gross rent and starts analyzing net operating income — rents minus a vacancy factor minus operating expenses. The math gets stricter.
• Expect a rate premium over a comparable residential loan and a more involved, slower close with more documentation on the property’s operations.

None of that makes a five-unit a bad investment. It just means the financing lives in a different category with a higher cost of capital. If your goal is the cleanest, cheapest leverage, the fourplex is the largest property that keeps you on the residential side of that wall.

Running your numbers before you offer

Everything hinges on appraised market rent versus PITIA, so do the work before you write an offer. Pull realistic rent comps for each unit, estimate non-homestead taxes and investment-property insurance for the specific building, add any association dues, and divide the combined rent by the total payment. Land above 1.00 and you have a financeable deal; the closer you get to 1.20, the better your pricing.

A fourplex gives you a built-in advantage here: if one unit sits vacant, three are still paying. That diversification is exactly why the combined coverage on four doors tends to beat a single-family deal at the same price point. If you’re comparing across the class, the step down to a triplex DSCR loan trades a bit of that coverage cushion for a slightly lower entry price and reserve requirement.

The appraisal is where fourplex deals are won or lost

On a single-family DSCR loan the appraisal is straightforward — one set of comps, one market-rent figure. A fourplex is more involved, and the extra complexity is exactly where deals slow down or fall apart, so it’s worth understanding before you order the report.

The appraiser works from Form 1025, the small-residential-income appraisal form, and attaches a Form 1007-style rent schedule that assigns a market rent to each of the four units. Two things make this trickier than a single-family report. First, comparable four-unit sales can be thin in many neighborhoods, so the appraiser may have to reach further for comps or lean harder on the income approach. Second, the rent schedule has to be supported unit by unit — a studio, a one-bedroom, and two two-bedrooms in the same building each need their own rent comps. A weak or poorly supported rent schedule drags the qualifying rent down, and because qualifying rent is the numerator of your DSCR, a soft appraisal can quietly push a deal that pencils on paper below the lender’s coverage floor.

Protect yourself by doing the appraiser’s homework before they arrive. Pull recent lease comps for each unit type in the immediate area and have them ready. Make sure all four units are accessible on appraisal day — a unit the appraiser can’t enter can come back with a conservative rent estimate or trigger a re-inspection that delays the close. If a unit is mid-turn, present a signed lease or a market-rate listing for the vacant space. The more support the appraiser has for full market rent on every door, the cleaner your DSCR comes back and the less likely you are to scramble for a rate-and-term adjustment late in the process.

Bottom line

A fourplex is the most income you can finance without leaving residential DSCR territory. Four rent rolls produce strong combined coverage, the underwriting stays simple, and you keep 30-year fixed terms and the tightest available pricing. Bring 25% down, stack a deeper reserve cushion, and get the combined rent comfortably above the payment. Just know where the wall is — at the fifth unit the loan goes commercial, so the fourplex is the deal to maximize before that switch flips.