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 a long list of operating expenses comes out of that gross (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 below pro forma because the STR's real operating costs were never itemized.

Should I trust AirDNA's projections?

AirDNA is the best single source we have, but treat its projections as a starting point. 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 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 then discount it for (a) being a new listing without reviews, (b) bookings clustering in peak months, so the off-season fills slower than the annual average suggests, and (c) cancellations and gap nights between bookings that raw occupancy data doesn't fully capture. Size that discount from your comps' evidence and disclose it, rather than applying a universal haircut.

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

It varies by property, market and management model; build it line by line from the list below rather than assuming a ratio. The full list: cleaning fees (often passed through but with shortfall risk), supplies and restocking (priced per turnover from your own supplier quotes), channel fees (each platform publishes its host fee; check the current rate before you model it), dynamic pricing software (check each vendor's current pricing), 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 (budget from the property's condition and local contractor quotes).

How should I stress-test an STR deal?

Build a reviewed base case from relevant dated comps, one or more adverse revenue/cost cases tied to observed local volatility, and a lawful fallback-use case if one exists. Disclose each change rather than applying a universal haircut. Compare the cash needs with your actual capacity and verify regulations, insurance, financing, taxes, and property restrictions. No scenario output makes the deal acceptable or tells you to walk.

Are STR loans different from long-term rental loans?

Mostly the same products with caveats. Conventional loans can count short-term rental income on one-unit investment properties, but under their own documentation rules — Fannie Mae's Selling Guide has a separate section for short-term rental income from the subject property — so ask the lender how STR income will be documented. DSCR lenders differ on whether they use long-term market rent or short-term rental history to compute DSCR; ask each lender which income it will count. Some lenders may count projected STR revenue toward DSCR; ask how they discount it and how it affects pricing, and compare written quotes. 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 needs a full furnishing package (furniture, mattresses, kitchen kit, decor, smart locks, outdoor furniture, photography); price it from real quotes. Then budget an annual replacement reserve: divide the package cost by the years you expect it to last and treat that as an operating cost.

Short-term rental underwriting playbook (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 looks so obviously better that it's tempting to skip running it carefully.

STRs aren't worse than long-term rentals — some produce more 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, an assumed 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 looks different to an investor who borrows a long-term-rental OpEx ratio of 40%: $300 × 0.55 × 365 × 0.60 = $36,135 NOI − $50,400 = −$14,265/yr. Shave OpEx to 35% and it's $39,146 NOI minus $50,400 debt service = −$11,254/yr (still bad, but feels survivable). Now imagine the bullish-version investor who also 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 starting point

AirDNA tracks Airbnb and Vrbo listings and publishes market-level and property-level analytics. Its Rentalizer tool gives you projected ADR, occupancy, and revenue for a specific property address. It's the best single source — but treat it as a starting point, not the answer, and check it against the comps you pull yourself.

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 PriceLabs Market Dashboard, a paid product (check current pricing), can show median booked prices alongside a market's median listed prices — 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 and Vrbo each publish their host fees; check the current rate on each platform before you model it. Direct bookings via your own site (Hostfully, Lodgify) cut this materially.
Supplies and restocking. Priced per turnover for coffee, paper goods, soap, hot tub chemicals — use your own supplier quotes.
Dynamic pricing software. PriceLabs, Wheelhouse or similar; check each vendor's current pricing.
Channel manager / PMS. Hostfully, Hostaway, Guesty. Pricing varies by vendor and listing count; get a current quote from each vendor.
Damage / overage. Even with deposits and guest insurance, some damage may go unrecovered — budget a reserve for it.

Fixed costs (don't scale with bookings)

Utilities. You pay them all, year-round. Plan for higher utility costs than a long-term rental, estimated from the property's actual utility history.
Internet, streaming subscriptions. Price from local provider quotes.
Lawn / pool / hot tub service. Weekly in season. Cost depends on the amenity set; get local service quotes.
Pest control. Often monthly; get a local quote.
STR-specific insurance. Get a binding quote for a policy that covers short-term rental use.
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: periodic replacement of furniture, mattresses, decor, kitchen equipment and listing photography, plus big-ticket items like hot tubs.

Add it up: a $35K furnishing package you expect to replace every 7 years, for example, amortizes to ~$5K/year in true operating cost. Don't put 0 here.

Modeling seasonality properly

STRs don't book evenly across the year. A hypothetical mountain 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 relying on an STR model, build separate, disclosed scenarios that reflect the evidence and risks for the property. There is no universal number of scenarios or haircut.

Scenario 1: Base case

Use dated ADR, occupancy, seasonality, and cost evidence from a relevant comp set. Itemize the operating model and label every assumption that is not property-specific.

Scenario 2: Bad year

Vary revenue, occupancy, costs, and startup ramp using ranges tied to relevant local history and the property's uncertainty. Explain why each change was selected; do not present a generic percentage as a market forecast.

Scenario 3: Regulatory shock

Verify current permitted use, licensing, transferability, HOA or building rules, enforcement, insurance, financing, and taxes with authoritative local sources. If another rental use is lawful, model it separately from reviewed rent and cost evidence. The result describes a scenario; it does not decide whether to proceed.

Verify current rules for the exact property

Rules can differ by jurisdiction, zone, building, unit, ownership, permit history, and date—and can change. Check the current ordinance, zoning and licensing authorities, tax agency, HOA or condominium documents, insurer, and lender. A city-level blog summary cannot establish that the property may operate as an STR.

Keep any unresolved permission or transfer question explicit in the model and contract review. Do not capitalize STR revenue until the relevant evidence supports the assumed operation.

Financing has its own STR rules, too. Conventional loans can count short-term rental income on one-unit investment properties, but under their own documentation rules — Fannie Mae's Selling Guide has a separate section for short-term rental income from the subject property — so ask the lender how STR income will be documented.

Is the operating model within your capacity?

Review questions such as:

What staffing, response, cleaning, maintenance, and guest obligations apply?
What reserves and liquidity do the adverse scenarios require?
Which revenue, cost, and permitted-use assumptions remain unverified?
What management proposal and contract terms are actually available?

The answers are property- and operator-specific. Use them to inform professional review and your own decision process rather than a universal STR-versus-LTR rule.

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