Verify what you are buying before valuing it
The spreadsheet cannot repair a bad property definition. Confirm the parcel, deeded owner, legal unit count, zoning, Certificate of Occupancy status, tax class, current occupancy, utilities, and physical access before assigning income to every advertised bedroom or unit.
This matters acutely in the City of Rochester: one- through three-family residential properties generally fall under the published homestead tax rate, while other property falls under the non-homestead rate. A four-unit presented as if it were taxed like a duplex can create a material underwriting error.
- Match the listing and rent roll to the legal use and C of O
- Confirm which units were physically inspected
- Save current tax, water, utility, insurance, lease, and ledger evidence
- Record every unresolved fact as an assumption—not as a verified input
Keep four versions of the property separate
A single “pro forma” usually hides which changes are doing the work. Preserve separate cases so the investor can see what exists today and what must happen to reach the plan.
| Case | What belongs in it |
|---|---|
| Current | Existing leases, actual occupancy, current expenses, and present condition |
| As-is buyer | Current property operated under the buyer’s realistic management and financing structure |
| Renovation period | Lost rent, construction, permits, carrying costs, draws, and phased occupancy |
| Stabilized | Completed scope, supportable rents, normal vacancy, and recurring stabilized expenses |
Build scheduled income from the unit level
Start with one row per legal unit. Record tenant status, lease dates, contract rent, concessions, assistance payments, deposits, arrears, utility responsibility, renewal status, and the evidence date. Then reconcile the unit schedule to bank deposits or the owner ledger.
Market rent belongs in a separate column with a source, sample period, property type, location, and adjustment notes. Asking rent is not collected rent, and one renovated listing is not evidence that every occupied unit can immediately achieve that number.
- Gross potential rent from the unit schedule
- Less concessions and recurring discounts
- Less physical vacancy and downtime
- Less credit loss, delinquency, and bad debt
- Plus supported recurring laundry, parking, storage, or reimbursement income
- Equals effective gross income
Vacancy is more than an empty-unit percentage
Physical vacancy measures empty units. Economic vacancy measures rent not collected compared with rent that could have been collected. A unit can be occupied but economically vacant because of nonpayment, concessions, employee use, or a missing lease. A unit can also be empty for make-ready, renovation, casualty, legal restriction, or deliberate owner use.
For each vacant or nonperforming unit, track the reason and days in stage: notice, possession, scope, pricing, work, inspection, marketing, application, lease signing, and move-in. That produces a usable operating assumption instead of a mystery percentage.
Include every recurring operating expense
Net operating income is effective gross income less recurring property-level operating expenses before debt service, income taxes, depreciation, and major capital work. If an expense is missing, the result is an incomplete subtotal—not NOI.
Use actual trailing records as the starting evidence, then explain every normalization. An owner who self-manages, performs free labor, defers maintenance, or carries unusually low insurance does not make those economic costs disappear for the next investor.
- All real-property taxes and property-specific charges
- Insurance for the actual use, units, occupancy, and renovation plan
- Owner-paid water, sewer, gas, electric, refuse, and common utilities
- Management, leasing, advertising, screening, bookkeeping, and legal/compliance
- Repairs, ordinary maintenance, pest control, grounds, and snow
- Licenses, C of O, inspections, lead compliance, and recurring municipal costs
- A clearly disclosed replacement reserve below NOI when it is not treated as an operating expense
Sources
Rochester property-tax guideKeep repairs, capital work, and renovation apart
Ordinary repairs and maintenance preserve current operation and belong in the recurring expense view. A roof replacement, structural repair, major system replacement, full unit rehabilitation, or conversion belongs in a dated capital plan. A replacement reserve is a planning allowance; it is not proof that a known $40,000 roof costs only the annual reserve amount.
For a value-add deal, create a scope with quantities, bids or unit costs, permits, design, disposal, lead-safe practices, tenant phasing, contingency, schedule, and carrying cost. The acquisition decision should show total cash required before stabilization—not merely the down payment.
Analyze financing after property-level NOI
Debt service is not subtracted to create NOI or cap rate. Analyze the property first, then layer in the loan: amount, rate, term, amortization, interest-only period, points, lender fees, escrow, reserves, recourse, covenants, prepayment, construction draws, and refinance assumptions.
Debt-service coverage ratio equals NOI divided by annual debt service. Cash flow after debt is NOI less debt service, with any planned capital reserve shown explicitly. Cash-on-cash return should use the investor’s actual cash invested, including closing, renovation, financing, and required reserve cash—not down payment alone.
- Cap rate = NOI ÷ purchase price
- Yield on cost = stabilized NOI ÷ total acquisition and project basis
- DSCR = NOI ÷ annual debt service
- Cash flow after debt = NOI − debt service
- Cash-on-cash return = annual pre-tax cash flow ÷ actual cash invested
Worked example: a hypothetical Rochester four-unit
This is an arithmetic demonstration, not a listing, comp, recommendation, or statement of typical Rochester performance. Assume four legal units at $1,250 monthly rent, a $400,000 purchase price, $12,000 closing costs, $50,000 immediate capital work, and a $300,000 loan at a hypothetical 7% fixed rate amortized over 30 years.
Because the example is a City four-unit, it uses the City’s published 2026–27 non-homestead rate-based total of $32.434701 per $1,000 against a hypothetical $200,000 assessment. Actual bills can also include other charges, and a real acquisition must use the property record.
| Annual calculation | Amount |
|---|---|
| Scheduled residential rent | $60,000.00 |
| Vacancy and credit loss — assumed 5% | −$3,000.00 |
| Effective gross income | $57,000.00 |
| Rate-based property tax illustration | −$6,486.94 |
| Insurance — hypothetical | −$4,200.00 |
| Owner-paid water/common utilities — hypothetical | −$3,600.00 |
| Management — assumed 8% of collected rent | −$4,560.00 |
| Repairs and maintenance — assumed | −$2,850.00 |
| Grounds and snow — assumed | −$1,200.00 |
| Administration and recurring compliance — assumed | −$800.00 |
| Total operating expenses | −$23,696.94 |
| Net operating income | $33,303.06 |
Read the example through several lenses
The 8.33% cap rate does not mean the investor earns 8.33% on all cash or total project cost. The lower 7.21% yield on cost exposes the closing and immediate-capital burden. Financing then reduces the hypothetical annual cash after the planned reserve to $5,352.17.
| Measure | Calculation | Result |
|---|---|---|
| Going-in cap rate | $33,303.06 ÷ $400,000 purchase price | 8.33% |
| Total project basis | $400,000 + $12,000 + $50,000 | $462,000 |
| Yield on total cost | $33,303.06 ÷ $462,000 | 7.21% |
| Annual debt service | $300,000; 7%; 30-year amortization | $23,950.89 |
| DSCR | $33,303.06 ÷ $23,950.89 | 1.39× |
| Planned capital reserve | Shown below NOI | $4,000.00 |
| Pre-tax cash after debt and reserve | $33,303.06 − $23,950.89 − $4,000 | $5,352.17 |
Stress the variables that can actually break the deal
Do not stop at a polished base case. Change one variable at a time, then combine credible adverse cases. In the example, a 15% increase in the illustrated rate-based tax reduces annual NOI and cash flow by about $973.04. A 25% insurance increase reduces them by $1,050. A 10% vacancy assumption—while holding the other stated expense assumptions—reduces NOI to about $30,543.06 and cash after debt and the planned reserve to about $2,592.17.
Then test a combined case: lower rent, longer construction, higher vacancy, repair overruns, tax or insurance changes, interest movement, delayed refinance, and a softer exit. A deal that works only when every variable improves is not a base case.
Rent growth must respect the operating and legal reality
A rent increase may require turnover, renovation, notice, renewal, or a different tenant—and each has cost and timing. Rochester is covered by New York’s Good Cause Eviction framework for non-exempt housing accommodations. Coverage, exemptions, notices, and permissible renewal strategy are property- and owner-specific.
Underwrite current leases as current income. Put renewal increases, turnover, and post-renovation rents on a dated schedule with legal review, leasing cost, downtime, work, and probability. Do not treat every unit as simultaneously vacant, renovated, and re-leased at the best advertised rent.
Finish with an evidence-based decision
The purpose of underwriting is not to generate the highest return percentage. It is to expose what must be true, what can be verified, what cash is required, and which failure modes the investor can survive.
This guide is educational and the worked example is wholly hypothetical. Rates and laws were reviewed September 9, 2026. Verify the property-specific record and obtain appropriate legal, tax, lending, insurance, environmental, engineering, and accounting advice.
- Verified current case with every known recurring expense
- Renovation-period monthly cash requirement and contingency
- Stabilized case with support for every changed rent and expense
- Capital schedule kept separate from NOI
- Financing case with DSCR, cash flow, covenants, and refinance risk
- Downside and break-even views
- Open-item register identifying seller facts, assumptions, missing evidence, and decision owner
- Written approve, renegotiate, extend, or terminate decision