Most underwriting mistakes don’t look reckless at the time. They look reasonable. They’re usually based on what just worked, what lenders recently tolerated, or what brokers stopped pushing back on.
What I’ve noticed is that Florida punishes lagging assumptions faster than most markets. Not because it’s volatile in a dramatic way, but because it’s liquid, competitive, and heavily intermediated. When conditions change, the margin for “mostly right” underwriting disappears.
This isn’t about predicting a crash or a boom. It’s about recognizing which assumptions quietly embed fragility into a deal—especially for 50–150 unit properties in South and Central Florida, where execution risk matters more than macro headlines.
Below are the assumptions I see creeping into models that feel survivable today, but could be fatal by 2026.
1. Assuming Rent Growth Is the Primary Risk Variable
Florida underwriting still spends too much time arguing over whether rent growth is 2% or 4%.
That’s not where deals break.
What actually matters is rent realization under friction:
- Loss-to-lease that takes longer than expected to burn off
- Concessions that become sticky, not temporary
- Renewal trade-offs where pushing rent increases occupancy volatility
In many Florida submarkets, headline rent growth is less important than how quickly units reset and how much resistance shows up at renewal.
What I’ve noticed is that models assume smooth rent curves in markets where tenant churn, seasonality, and competitive supply make rent behavior lumpy. Florida doesn’t glide—it resets in steps.
2. Treating Expense Growth as Linear and Predictable
A lot of underwriting still treats expenses like a spreadsheet exercise:
- Payroll up 3%
- Repairs up 4%
- Insurance “normalized” after last year’s shock
That’s not how Florida expenses behave.
Insurance, property taxes, utilities, and contract services move in jumps, not lines. They’re driven by:
- Carrier pullbacks, not just rate increases
- County reassessments that lag purchase price, then catch up all at once
- Vendor consolidation that quietly removes pricing power
If your expense model assumes mean reversion, you’re underwriting hope.
By 2026, the danger isn’t that expenses rise—it’s that they don’t fall back the way your model assumes they will.
3. Underwriting to Exit Cap Narratives Instead of Liquidity Reality
Exit cap assumptions tend to be justified with sentences like:
“Florida is a growth market with strong long-term fundamentals.”
That’s not underwriting. That’s branding.
What actually sets Florida pricing is who is active at your exit size and vintage:
- Institutional buyers often won’t touch smaller assets with operational scars
- Local operators are price-sensitive and financing-constrained
- Private capital is fickle when liquidity tightens
In 50–150 unit deals, exit pricing is less about macro sentiment and more about:
- How clean your operations look
- Whether the buyer pool trusts your trailing numbers
- How many alternatives they have in that quarter
If your exit cap relies on capital coming back, not buyers showing up, it’s fragile.
4. Assuming Permanent Debt Will Be Available on Reasonable Terms
This one is subtle, because it’s often buried in lender quotes that look fine today.
Florida deals frequently assume:
- Takeout debt exists
- Proceeds are “roughly” what today’s agencies are offering
- DSCR will pencil with modest NOI growth
But agency and bank appetite changes faster than most models acknowledge—especially for:
- Older assets
- Secondary locations
- Properties with uneven collections or insurance history
What I’ve noticed is that underwriting often assumes terms continuity. In reality, Florida lending is cyclical and reputation-driven.
By 2026, the risk isn’t no debt—it’s debt that exists, but not at the leverage or pricing your model quietly needs.
5. Treating Operational Execution as a Rounding Error
Florida underwriting loves clean pro formas:
- Renovation premiums hit on schedule
- Vacancy stabilizes smoothly
- Payroll scales neatly with unit count
But operations here are noisy:
- Labor turnover is real
- Property management quality varies wildly
- Weather, seasonality, and tenant mix matter more than spreadsheets suggest
On 80- or 120-unit deals, one bad quarter of execution can erase a year of projected upside.
If your underwriting works only if operations are tight, it’s not conservative—it’s conditional.
6. Assuming Liquidity Will Save You from Mediocrity
This is the most dangerous assumption of all.
Florida has trained investors to believe:
“If it’s not perfect, you can still sell.”
Sometimes that’s true. Sometimes liquidity masks weak deals.
But liquidity is cyclical, and when it fades, mediocre deals don’t clear at ‘okay’ prices—they just don’t trade.
By 2026, the risk isn’t being wrong—it’s being slightly wrong in a market that no longer forgives it.
A Better Framing for Florida Underwriting
Instead of asking:
- “What’s the rent growth?”
- “Where do exit caps go?”
I’ve found it more useful to ask:
- Where does this deal rely on continuity?
- Which assumptions break first if friction increases?
- Who is the marginal buyer really?
Florida rewards operators who underwrite behavior and structure, not stories.
The deals that survive aren’t the ones with the best spreadsheets. They’re the ones that still function when assumptions stop cooperating.
And that’s usually decided long before 2026 shows up.