Multi-family analysis uses the same building blocks as single-family — NOI, cap rate, cash flow — but scale changes the math. A 10-unit building has more stable cash flow than a single-family home but requires more rigorous underwriting.

Key Multi-Family Metrics

Gross Scheduled Income (GSI) = All units × monthly rent × 12 Effective Gross Income (EGI) = GSI × (1 - vacancy rate) Net Operating Income (NOI) = EGI - operating expenses Cap Rate = NOI / purchase price × 100 DSCR = NOI / annual debt service

Debt Service Coverage Ratio (DSCR)

DSCR is critical for multi-family financing. Lenders require DSCR of at least 1.25x — meaning NOI covers debt service 1.25 times over. Below 1.0x, the property can't service its own debt. A DSCR of 1.4x+ gives a comfortable safety margin.

Using Zip Code Data for Multi-Family

ZipMarketData's HUD rental data covers all bedroom types (BR0–BR4) — useful for underwriting mixed-unit buildings. The market temperature and DOM data helps assess exit strategy risk: difficult to sell into a cool market if you need to refinance or sell at end of hold period.

Value-Add Screening

Identify value-add opportunities by comparing current rents (from current owner's rent roll) against HUD SAFMR benchmarks for the ZIP code. A property with rents 20%+ below SAFMR has clear upside — either from renovating units to market standard or from simply allowing leases to roll to current market rates.