Pillar · Multifamily
Multifamily Underwriting
Underwrite apartment deals from the rent roll down: gross potential rent to NOI, the broker pro-forma vs the true (post-reserves) number, DSCR and cash-on-cash, and where value-add upside really comes from.
Two value levers get conflated constantly — and they're underwritten differently
Loss to lease is captured for free. When in-place rents sit below market, simply renewing at market closes the gap with no capital spent — the lowest-risk upside in any deal. But sellers price it in, so verify how much loss to lease is actually left.
Value-add requires capital and a return test. Pushing rents above market through renovation costs money; you underwrite it on return-on-cost — incremental NOI ÷ renovation spend — against your cost of capital and exit cap. A value-add renovation that yields below your exit cap destroys value even as rents rise.
Expense ratios are the credibility check. An operating-expense ratio well below market for the asset class and vintage means the income is overstated or the expenses are — the kind of check the multifamily underwriting guide builds in.
| Lever | Rent move | Annual revenue | Capital |
|---|---|---|---|
| Loss to lease (renew to market) | $1,200 → $1,350 | +$180,000/yr | $0 |
| Value-add (renovate above market) | $1,350 → $1,500 | +$180,000/yr | $1,200,000 ($12k/unit) |
The loss-to-lease gain is essentially free — you're stopping a leak. The value-add gain must earn its keep. Assuming ~90% of incremental renovation rent flows to NOI:
- Incremental NOI ≈ $162,000/yr
- Return on cost = $162,000 ÷ $1,200,000 = 13.5%
- Value at a 5.5% exit cap = $162,000 ÷ 0.055 = $2,945,000, against $1,200,000 spent → ~$1.75M created
The discipline: underwrite the levers separately. Loss-to-lease is near-certain and capital-free; value-add only works when return-on-cost comfortably beats your exit cap. Blending them into one "stabilized rent" hides which dollars are safe and which are at risk.
How are these numbers computed? See how UpsideIQ underwrites →
Free calculators
Multifamily Pro Forma Calculator
Units in, returns out — GPR, NOI, cap rate, DSCR, and cash-on-cash in one quick estimate.
Open the calculator → CalculatorDSCR Calculator
Check whether NOI covers debt service — the first test every lender runs.
Open the calculator → CalculatorCap Rate Calculator
See the broker cap and the true (post-reserves) cap side by side — the gap sellers don't show you.
Open the calculator →Guides & teardowns
Multifamily Operating Expense Ratio (OER)
Understand the multifamily operating expense ratio — how to calculate OER from expenses and EGI, what range is normal, and why a low OER is a red flag.
Read → asset-playbookLoss to Lease, Explained
Loss to lease explained — what it is, how to calculate the gap between in-place and market rents, and why it is upside you capture with zero capital.
Read → asset-playbookMultifamily Cash-Out Refinance Underwriting
Multifamily cash-out refinance underwriting — how to size a new loan from stabilized NOI, pay off existing debt, and return capital while DSCR holds.
Read → asset-playbookHow to Analyze a Rent Roll
Learn how to analyze a rent roll for a multifamily deal — read in-place vs market rents by unit type, quantify loss to lease, and spot risk.
Read → asset-playbookValue-Add Multifamily Underwriting
A practical guide to value-add multifamily underwriting — sizing renovation cost, rent lift, return on cost, and the value created at exit cap.
Read → TeardownThe Multifamily Deal That Cash-Flows on Paper but Won't Get Financed
A stabilized multifamily deal at a clean 6% cap rate that still failed at the lender — why DSCR, not cap rate, sized this loan, and how to spot a debt-service-constrained deal early.
Read → TeardownWhy I Passed on a “6.5% Cap” Multifamily Deal That Was Really a 4.9%
A teardown of a value-add multifamily deal — how a broker's 6.5% stabilized cap became a sub-5% true cap once reserves, real vacancy, and P&I debt went in.
Read → asset-playbookHow to Underwrite a Multifamily Deal
A step-by-step multifamily underwriting playbook — rent roll to GPR, vacancy, expenses and reserves, NOI, exit cap, and the DSCR and IRR that decide the deal.
Read →Key terms
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