Purpose of due diligence
Due diligence is the period between an accepted offer and closing when you verify what you have been told and what you assumed. The goal is to find deal-breakers, negotiate adjustments, or exit before closing. Build a timeline at the start, since inspection, permit, and loan deadlines often overlap. Read your purchase contract to see what contingencies and deadlines apply, and ask an attorney or agent to explain the contract terms.
Part 1: Legal and regulatory
- Confirm short-term rentals are allowed on the parcel (see the permits and zoning checklist).
- Confirm permit status, transferability, and any caps or waitlists.
- Review HOA or condo documents for rental restrictions, fees, and assessments.
- Order a title search and review liens, easements, and encroachments.
- Check for open code violations or unpermitted work.
- Verify the occupancy limit and septic capacity, if relevant.
- Confirm lodging tax registration needs (see occupancy tax basics).
Part 2: Physical condition
- Full home inspection by a licensed inspector
- Specialist inspections as needed: roof, HVAC, plumbing (including a sewer scope), electrical, foundation, pool or hot tub, septic, well, pest
- Flood zone and environmental hazards; check maps and insurance requirements
- Access and parking: road conditions, seasonal access, driveway grade
- Age and remaining life of major systems (feed this into reserve planning)
- Neighborhood conditions: noise, construction, and nearby developments
Part 3: Financial verification
- If the seller has operated it as a rental, request booking history, platform statements, and utility bills, and compare with tax and lodging filings where the seller is willing to share.
- Verify property taxes and expected reassessment after sale.
- Get insurance quotes for short-term rental use, including wind, flood, and liability, before you close.
- Confirm HOA dues and special assessments.
- Rebuild your underwriting with verified numbers (see underwriting basics).
- Confirm loan terms and rate lock, and any conditions related to rental income.
Part 4: Market and revenue
- Pull current comps and cross-check estimates (see reading AirDNA data).
- Verify seasonality and event dependence.
- Check supply trends and pending regulation changes.
- Review existing reviews of the property, if it is already listed, for recurring complaints.
- Talk with at least one local property manager about realistic performance.
Part 5: Operations readiness
- Identify cleaners, maintenance vendors, and a manager, and get quotes.
- Plan the furnishing timeline and budget.
- Confirm internet availability and quality, plus cell coverage.
- Confirm trash service, snow removal, or other local service needs.
- Plan launch date, photo shoot, and listing setup.
Red flags
- The seller cannot show that the permit exists or transfers.
- Revenue claims with no supporting statements.
- Unpermitted additions or extra bedrooms that raise the listed capacity.
- Significant deferred maintenance that the price does not reflect.
- Insurance that is unavailable or extremely costly.
- HOA rules that are unclear or recently changed.
- A market where new supply is rising sharply and demand looks flat.
Decision framework
- Sort findings into deal-breakers, negotiable items, and acceptable risks.
- Price the negotiable items: request repairs, credits, or a lower price with supporting quotes.
- Re-run the underwriting with the updated numbers and stress tests.
- Compare the result to the minimum return and maximum loss you decided in advance.
- Proceed, renegotiate, or terminate within your contingency deadlines.
Example (illustrative only): An inspection finds a roof needing replacement at $15,000 within three years, and your underwriting had a $9,000 reserve for it. You could ask for a $6,000 credit or a price reduction, or accept the risk if the numbers still work. Decide with your agent and attorney.
Common mistakes
- Letting a contingency deadline pass before permit answers arrive
- Skipping specialty inspections to save a few hundred dollars
- Trusting the seller's or listing agent's revenue claims without documentation
- Skipping insurance quotes until after closing
- Emotional attachment to the deal after spending money on inspections
Organizing the process
Create a shared folder and a tracking sheet with each item, the person responsible, the deadline, and the status. Order long lead-time items first: permits, title work, specialty inspections, and insurance quotes. Review the sheet every few days so nothing slips before a contingency deadline.
Who to involve
- A real estate agent familiar with rentals in the area
- A real estate attorney, especially where permits or HOA rules are complex
- A licensed home inspector and specialists
- A lender or mortgage broker
- An insurance agent
- A local property manager or cleaner for an operations check
Each specialist reduces a different risk, and their combined findings give you a fuller picture than any single review.
Key takeaways
- Start the longest lead-time items first, especially permits and insurance quotes.
- Ask for documents that support any revenue claim.
- Sort findings into deal-breakers, negotiable items, and acceptable risks.
- Decide your walk-away criteria before you emotionally commit.
Finally, keep every report, quote, and email in one place, since these documents also help with future insurance claims, lender questions, and resale conversations.
Educational only: this guide is general education, not legal or financial advice; consult qualified professionals for your transaction.