Short-term rental underwriting playbook: how to model an Airbnb in 2026

Short-term rentals look great on paper. A 3-bedroom mountain cabin renting for $300/night at 60% occupancy grosses ~$65K/year — far more than the $2,200/month ($26K/year) it would pull as a long-term rental. The math is so obviously better that thousands of investors entered the space between 2020 and 2024 without running it carefully. Many of them are now distressed sellers.

STRs aren't worse than long-term rentals — many produce 2-3x the cash flow. But they hide costs and risks long-term-rental underwriting misses entirely. This post is the full playbook: what to model, where to get the data, what hidden costs everyone forgets, and how to stress-test for a bad year.

The three numbers that decide an STR

Every other input matters at the margin. These three decide whether the deal is profitable:

ADR (average daily rate) — what guests actually pay per night, blended across all seasons.
Occupancy — what percent of available nights are booked across the year.
Operating expense ratio — what percent of gross revenue gets eaten by costs (cleaning, supplies, utilities, channel fees, etc.).

Gross revenue = ADR × Occupancy × 365. Net operating income = Gross × (1 − OpEx ratio). Cash flow = NOI − debt service. Everything else is detail.

Annual cash flow = (ADR × Occ × 365 × (1 − OpEx%)) − Annual debt service

Worked example. Cabin at $300 ADR, 55% occupancy, 60% OpEx ratio, $4,200/mo PITI:

Gross: $300 × 0.55 × 365 = $60,225
NOI: $60,225 × 0.40 = $24,090
Annual debt service: $4,200 × 12 = $50,400
Cash flow: $24,090 − $50,400 = −$26,310/year

That same deal pencils for an investor who got the OpEx ratio wrong: $300 × 0.55 × 365 × 0.65 = $39,146 NOI minus $50,400 debt service = −$11,254/yr (still bad, but feels survivable). Move OpEx to 40% (long-term-rental thinking): $36,135 NOI − $50,400 = −$14,265/yr. Now imagine the bullish-version investor who assumes 70% occupancy: $300 × 0.70 × 365 × 0.65 = $49,820 NOI − $50,400 = −$580/yr — basically break even.

Same property, four different conclusions, all driven by which of the three numbers you flex. That's why STR underwriting requires discipline.

Where to get ADR and occupancy data

1. AirDNA — the institutional starting point

AirDNA scrapes Airbnb and VRBO and publishes market-level and property-level analytics. Their MarketMinder and Rentalizer tools give you projected ADR, occupancy, and revenue for a specific property address. Most institutional STR investors use it. It's the best single source — but treat it as a starting point, not the answer. Coverage is excellent in established STR markets and weaker in emerging ones.

2. Direct comp pulls from Airbnb and VRBO

This is the work AirDNA does, manually, for your specific property. Pull 5-10 active listings within a half-mile that match yours on bedrooms, hot tub, view, and standout amenities. For each:

Read 60-day-out and 90-day-out availability calendars to gauge near-term booking pace.
Sort by review count; ignore listings with under 20 reviews (too new to calibrate against).
Note the published nightly rate at peak, shoulder, and off-season weekends.
Cross-check with VRBO — VRBO sometimes shows different calendars and pricing for the same property.

3. PriceLabs or Wheelhouse for granular pricing data

These dynamic pricing tools have access to real booked rate data (not just published rates). A free PriceLabs market dashboard gives you actual booked ADR by market and by bedroom count over the last 12 months — usually more honest than scraping published nightly rates.

4. The local property manager call

One 20-minute call with a local STR property manager is worth hours of data work. They'll tell you the real seasonality curve, what amenities are non-negotiable in this market, what new regulations are pending, and what the operating cost structure actually looks like. They'll pitch you on their management service afterward — pay it forward by considering them seriously even if you plan to self-manage.

The OpEx line items that get missed

STR OpEx is the single biggest source of pro-forma misses. Here's the full list of what runs through your P&L every year — well beyond what a long-term rental has:

Pass-through costs (mostly recovered, with shortfall risk)

Cleaning fees. Guests pay them, but if your cleaning fee is set below actual cost, you eat the gap on every turnover. Set the fee at 110% of actual cost.
Linens turnover. Sheets, towels, kitchen linens get used hard. Plan replacement every 12-18 months.

Variable costs (scale with bookings)

Channel fees. Airbnb charges hosts 14-16% of gross. VRBO is 8% commission plus per-booking service fee. Direct bookings via your own site (Hostfully, Lodgify) cut this materially.
Supplies and restocking. $30-80 per turnover for coffee, paper goods, soap, hot tub chemicals.
Dynamic pricing software. PriceLabs $20-50/mo, Wheelhouse similar.
Channel manager / PMS. Hostfully, Hostaway, Guesty $40-100/mo or 1-2% of revenue.
Damage / overage.Even with deposits and guest insurance, 1-2% of revenue annually goes to damage you can't recover.

Fixed costs (don't scale with bookings)

Utilities. You pay them all, year-round. Plan 2-3x long-term rental utility cost because guests run the AC at 65°F in August.
Internet, streaming subscriptions. $80-150/mo.
Lawn / pool / hot tub service. Weekly in season. $200-600/mo depending on amenity set.
Pest control. Monthly. $50-100/mo.
STR-specific insurance. 1.5-2.5x standard landlord policy. Proper / CBIZ / Steadily.
Permits, lodging tax remittance. Recurring annual cost plus ongoing compliance time.
Accounting / bookkeeping.STR P&Ls are materially more complex than long-term rentals.

CapEx amortization (the silent killer)

A long-term rental needs a roof and an HVAC. An STR needs that plus: furniture replacement every 5-7 years, mattresses every 4-5, decor refresh every 3-4 (Airbnb listings with dated photos convert poorly), kitchen equipment churn, photography refresh every 2-3 years, and bigger-ticket items like hot tubs that need replacement every 7-10 years.

Add it up and a $35K furnishing package amortizes to ~$5K/year in true operating cost. Most pro formas put 0 here.

Modeling seasonality properly

STRs don't book evenly across the year. A Smoky Mountains cabin might do 85% occupancy June-August and 25% February-March. Modeling with a flat 55% blended occupancy hides cash flow timing risk — you might have months where revenue doesn't cover the mortgage and you're burning operating reserves.

Better approach: pull monthly occupancy and ADR from your comps, build a 12-month grid, and look at the worst three months. Make sure you have at least 6 months of debt service in operating reserves to absorb that off-season cycle. Tighter than that and one bad winter sinks you.

The three-scenario stress test

Before signing the contract, run three scenarios. They take 10 minutes and save deals.

Scenario 1: Base case

Your blended ADR and occupancy from the comp set. OpEx ratio from the line-item buildup above (usually 55-65% for self-managed, 65-80% for full-service PM). This is the deal you're actually buying.

Scenario 2: Bad year

ADR −10%, occupancy −15 percentage points, OpEx +10%. This is roughly what 2020 looked like in many markets, what a recession looks like in discretionary-travel markets, and what year 1 looks like for a new listing competing against established hosts.

Scenario 3: Regulatory shock

STR conversion banned overnight. You operate as a long-term rental at market rent. If the long-term scenario at market rent produces a survivable cash flow (break-even or modestly negative you can absorb), the deal is acceptable. If it produces a $3K+/month bleed you can't sustain for 18 months while you sell, walk.

Markets with regulatory risk to watch in 2026

STR regulation has tightened dramatically since 2022. As of mid-2026, the markets with the most active regulatory pressure include: New York City (effectively banned at scale), most of New Orleans, parts of Honolulu and Maui, Palm Springs (cap on new permits), most of Vermont (escalating town-by-town caps), and Dallas (residential STR ban litigated then largely upheld). Several Tennessee and Florida vacation markets have moved from unregulated to permit-required.

None of this disqualifies a market. It just means your regulatory-shock scenario (#3 above) needs to be real. If the long-term-rental cash flow doesn't survive, you're taking concentrated regulatory risk you may not be pricing in.

When STR underwriting is worth it

STRs make sense for investors who:

Have 6+ months of operating reserves and stable W-2 or business income to absorb a bad year.
Are buying in markets with strong long-term rental demand as the floor.
Want active income economics (acceptable hands-on time or willingness to pay 20-25% for full-service PM).
Have specific local market knowledge or a property manager relationship that gives them edge.

STRs are not the right play for investors who want mailbox money, who only have 3 months of reserves, who plan to self-manage from across the country, or who are using the STR cash flow to qualify for further borrowing. Those use cases want a long-term rental in a stable market.

Underwrite an STR deal

FAQ

What's the most common mistake new STR investors make?

Treating gross revenue as cash flow. AirDNA shows you the top of the funnel — projected gross — but STRs eat 30-50% of gross in operating expenses (cleaning, supplies, channel fees, dynamic pricing tools, lawn care, utilities, internet, hot tub maintenance, restocking, owner labor). New investors plug AirDNA gross into a long-term-rental spreadsheet that assumes 40% OpEx ratio and the deal looks great. Then year one comes in 20-30% below pro forma because the OpEx ratio for an STR is closer to 55-65%.

Should I trust AirDNA's projections?

AirDNA is the best single source we have, but the projections are most reliable for established markets with deep comp pools (Smoky Mountains, Destin, Joshua Tree) and least reliable for emerging markets or unusual properties. Always pull at least 5-8 comparable active listings yourself on Airbnb and VRBO, sort by review count to filter out new listings, and check 60-day-out availability calendars to triangulate occupancy. Treat AirDNA's Investor-tier projections as a useful midpoint, not the answer.

How do I model occupancy realistically?

Use a blended occupancy that accounts for seasonality. Pull the 12-month occupancy series for your top 5-10 comps, take the median, and underwrite to 85% of that. The 15% haircut covers (a) you're a new listing without reviews, (b) bookings cluster in peak months so off-season fills slower than the annual average suggests, and (c) cancellations and gap nights between bookings aren't fully captured in raw occupancy data.

What's a realistic operating expense ratio for an STR?

55-65% of gross revenue for self-managed; 65-80% for full-service property management. The full list: cleaning fees (often passed through but with shortfall risk), supplies and restocking ($30-80 per turnover), channel fees (Airbnb 14-16%, VRBO 8% plus service fee), dynamic pricing software ($20-50/mo), lawn/pool/hot tub service, utilities (always included for guests), internet and streaming, linens replacement, OTA listing photography refreshes, software, accounting, lodging tax remittance, repairs at 2-3x long-term rental rates.

How should I stress-test an STR deal?

Three scenarios at minimum: (a) Base case = blended ADR and occupancy from your comp set. (b) Bad year = ADR -10%, occupancy -15 percentage points, OpEx +10%. This is roughly what 2020 looked like in many markets. (c) Regulatory shock = STR conversion banned, you operate as a long-term rental at market rent. If the long-term-rental scenario doesn't break you, the deal is acceptable. If it produces a $3K/month loss you can't sustain for 18 months, walk.

Are STR loans different from long-term rental loans?

Mostly the same products with caveats. Conventional investment-property loans don't distinguish STR from LTR — they qualify on personal income. DSCR loans usually compute DSCR based on long-term market rent (not projected STR revenue), which can make qualification tougher. Some specialty DSCR lenders will use AirDNA-projected STR revenue at 70-80% haircut to compute DSCR — these are great if available but typically charge 0.5-1.0pp above standard DSCR. Bridge and hard money work for STR acquisitions when you need speed.

What's the most under-appreciated cost in STR underwriting?

Furnishing CapEx is the biggest. A 3-bedroom STR typically needs $25-50K of furniture, mattresses, kitchen kit, decor, smart locks, hot tub, outdoor furniture, and photography to launch competitively in 2026. Then plan on 15-20% of that annually in replacement (mattresses every 4-5 years, sofas every 5-7, kitchenware ongoing, linens annually). Spread over 7 years that's another $5-7K/year in true operating cost most pro formas don't include.