The Cap Rate Bridge

Every real estate acquisition model, no matter how complex it gets, starts from the same four-step bridge. Get this sequence cold and you can underwrite a stabilized asset from a broker teaser in a few minutes, then layer CapEx, debt, and exit assumptions on top.

The short answer

"I bridge Gross Potential Rent to Effective Gross Income to NOI to value. Cap rate converts NOI into price: Value = NOI / Cap Rate. Lower caps mean higher prices for the same NOI. The usual interview traps are loss-to-lease annualization, putting CapEx inside NOI, and using trailing NOI at exit when the buyer underwrites forward NOI."

Step 1: Gross Potential Rent

GPR = Units x Market Rent per Unit x 12

This is the ceiling: what you would collect if every unit were occupied all year at the rent convention you chose (market or in-place). It is deliberately not "what we collect today." The rest of the bridge nets down from that ceiling. In interviews, say which rent basis you are using before you recite the math.

Step 2: Effective Gross Income

EGI = (GPR + Other Income) x (1 - Vacancy Rate) x (1 - Credit Loss)

Other income covers parking, laundry, pet fees, storage: recurring revenue that is not base rent. Vacancy is empty units; credit loss is billed rent that never collects. Models that only haircut vacancy and ignore credit loss overstate income when collections risk is real. Concessions (one month free, etc.) also sit in this net-down even when the OM is sloppy about labels.

The annualization trap

The most common multifamily interview plant is loss-to-lease. If in-place rent sits below market, a market-rent GPR overstates cash collected today. Value-add underwriting must bridge in-place to market over the business plan (often 12 to 24 months of turnover), not apply a flat vacancy haircut to a market GPR and call the asset stabilized. Skipping that is how a value-add deal looks already leased-up when it is not.

Step 3: Net Operating Income

NOI = EGI - Operating Expenses

Operating expenses: property taxes, insurance, utilities, repairs and maintenance, payroll, management fees (often a percent of EGI). NOI excludes capital expenditures, tenant improvements, leasing commissions, and debt service. Those live below NOI in the cash flow build. NOI is the real estate cousin of EBITDA: operating profit before financing and before capital decisions. If an OM pushes "reserves" into opex, ask the house convention before you capitalize.

Step 4: Value

Value = NOI / Cap Rate

A lower cap rate means a more expensive property, not a cheaper one. Cap rate is the yield the market requires. Core stabilized assets in strong markets trade at lower caps; value-add and opportunistic assets trade wider because investors demand more yield for execution risk. Never say "higher cap means higher value." That single flip fails screens.

Running the bridge at exit

The same four steps run at exit using forward NOI (what a buyer owns going forward), capitalized at an exit cap that is often assumed wider than entry as a conservatism buffer. Cap rates tend to drift out over a multi-year hold more often than they compress in base cases.

Exit Value = Forward NOI / Exit Cap Rate

Small cap moves matter: at a 5.0% cap, moving to a 5.5% exit cap cuts value by roughly 9% with NOI unchanged. That is why IC memos show cap rate sensitivity, not a single exit point. Leverage amplifies the equity hit when exit value falls.

Mechanics checklist

Why this bridge is the whole interview

Every REPE technical (DSCR, levered vs unlevered IRR, value-add vs core) is really asking you to reason about one step of this bridge. Get GPR to EGI to NOI to Value cold, know which leakages belong where, and the rest of modeling is more years and more detail on the same spine. If you can narrate the bridge on a blank page, most follow-ups become variations on leakage, CapEx, or exit yield.

Verbal 30 seconds

"I start with GPR, net to EGI with vacancy and credit loss, subtract opex to get NOI, then divide by cap rate for value. Exit uses forward NOI and usually a wider exit cap. CapEx and debt sit below NOI. Loss-to-lease is the trap when market rent is above in-place."

Related

NOI vs EBITDA, Exit Cap vs Going-In Cap, Cap Rate Interview Questions, and Interest Rates and Cap Rates.