My projected year-one cash flow was $14,000. My actual year-one loss was $52,000. Same building. Same market. Same investor. The difference was everything I assumed and nothing I verified.

I'm going to walk you through exactly what happened, what I missed, and what it cost me. Not because I enjoy reliving it, but because the lessons are worth more than what I lost. And if even one person reading this avoids the same mistakes, the tuition was worth it.

The Setup

The deal looked perfect on paper. A small multifamily in a submarket I knew well. The seller was motivated. The price was below what I thought the market supported. The rent roll showed occupied units paying rents that were already close to market. Cash flow from day one. Quick close. No drama.

I ran my numbers. They worked. I got excited. And that was the first mistake.

Excitement is the most expensive emotion in real estate. When you're excited about a deal, you start looking for reasons to say yes instead of reasons to say no. Every yellow flag gets explained away. Every question mark gets the benefit of the doubt.

I gave this deal every benefit of every doubt.

What I Missed

The Rent Roll Was a Fiction

The rent roll showed occupied units. What it didn't show was the reality behind those numbers. Three tenants were on month-to-month arrangements with verbal agreements, paying inconsistent amounts. Two tenants were more than 60 days behind on rent. One unit was "occupied" by a tenant who hadn't paid in four months but hadn't been formally evicted.

I looked at the rent roll and saw revenue. I should have looked at the bank statements and seen reality. The effective gross income was roughly 35% less than what the rent roll implied.

That alone should have killed the deal. It didn't, because I didn't dig deep enough before I was already emotionally committed.

The Deferred Maintenance Was Worse Than It Looked

I walked the property. I saw the cosmetic issues. Old carpet, dated kitchens, some peeling paint on the exterior. Standard value-add stuff. I budgeted accordingly.

What I didn't see was the plumbing. The building had galvanized steel pipes that were original to the construction. They looked fine from the outside. Inside, they were corroded to the point where water pressure was a constant tenant complaint, and pinhole leaks were popping up every few weeks.

The plumbing issue alone turned into a $38,000 expense in the first 14 months. I had budgeted $8,000 for plumbing repairs across my entire CapEx plan.

I didn't scope the plumbing because I assumed it was fine. The inspector noted the galvanized pipes in the report. I read that line and moved on. I should have called a plumber, run a camera through the lines, and gotten a real assessment. That would have cost me $400. Instead, I saved $400 and spent $38,000.

I Underestimated Turnover

Within the first 90 days of ownership, three tenants gave notice. Two of them were the ones who were behind on rent, which was expected. The third was a long-term tenant who didn't like the ownership change and decided to leave.

Each turnover cost between $4,000 and $6,000 when you add up lost rent during vacancy, make-ready-process-that-gets-units-leased-in-7-days) costs, and marketing to refill. That was $12,000 to $18,000 I hadn't modeled because my underwriting assumed stable occupancy.

The lesson: when you buy a property, assume you will lose 20-30% of the tenant base in the first year. Some will leave because of change. Some will leave because the previous owner was letting things slide and you won't. Some will leave because they were never properly screened in the first place.

Build that into your model. If the deal doesn't work with 25% turnover in year one, it doesn't work.

What It Cost Me

Here's the honest math.

Plumbing repairs beyond budget: $30,000

Turnover costs (3 units): $15,000

Lost rent from delinquent tenants: $8,400

Eviction legal costs: $3,200

Additional CapEx discoveries (electrical, water heater): $9,500

Total unexpected costs in year one: approximately $66,000

My projected year-one cash flow was $14,000. Instead, I was out of pocket $52,000 beyond what I expected to invest.

That isn't a rounding error. That's a different deal entirely.

The Five Lessons

1. Verify Income at the Bank, Not on the Rent Roll

A rent roll is a statement of what tenants are supposed to pay. Bank statements show what they actually pay. Those are often very different numbers. Request 12 months of bank statements and reconcile deposits against the rent roll line by line. If deposits don't match scheduled rents, you need to understand why before you close.

2. Budget CapEx Based on Inspections, Not Assumptions

Walking the property isn't enough. Bring a plumber if the building is older than 30 years. Bring an electrician if the panels look original. Bring a roofer if you can't get up there yourself. Every specialist costs a few hundred dollars. Every missed issue costs tens of thousands.

The specific rule I follow now: on any building built before 1985, I budget an additional 15-20% on top of my initial CapEx estimate as a contingency. If I don't use it, great. If I do, I'm not scrambling.

3. Model Turnover Aggressively in Year One

Post-acquisition turnover is real and it's expensive. New ownership always triggers some tenant movement. Plan for it. I now underwrite-a-multifamily-acquisition) 25% turnover in year one on any acquisition, regardless of how stable the tenant base appears.

If the deal works at 25% year-one turnover, it's a resilient deal. If it only works at 5% turnover, you're betting on a stability you can't guarantee.

4. Emotional Commitment Is the Enemy of Good Underwriting

The moment you start saying "I really want this deal to work," your underwriting is compromised. I have a rule now. If I catch myself rationalizing a yellow flag, I stop. I put the deal down for 48 hours. I come back with fresh eyes.

Most of the time, the yellow flag is still there. And most of the time, it looks worse after 48 hours of distance, not better.

5. Kill Criteria Must Be Defined Before You Start

Before I open a single document on a new deal, I write down the three to five things that would make me walk away. Non-negotiable kill criteria. Deferred CapEx above X. Tenant delinquency above Y. Expense ratio above Z.

If any kill criteria are triggered during due diligence, the deal is dead. No negotiation, no rationalization, no "well, maybe if we." Dead.

This rule has killed deals that my gut wanted to do. Every single time, I have been grateful three months later.

The Silver Lining

I still own the property. After the first 18 months of pain, the building stabilized. New tenants. Repaired plumbing. Updated units. The NOI today is actually above what my original projection was, it just took an extra $52,000 and a lot of stress to get there.

Would I do the deal again at the same price? No. I overpaid by roughly the amount of unexpected capital I had to inject. If I had underwritten properly, I would have either negotiated a lower price or walked away and found a deal with better bones.

The building is fine. My process was the problem. And the process is what I fixed.

Every deal I underwrite today runs through a framework that was built on the scar tissue from this one. I check the bank statements. I scope the plumbing. I model aggressive turnover. I define my kill criteria before I open the offering memorandum.

The worst deal I ever did made me a better investor. That doesn't make it a good deal. It makes it an expensive education.

Here's what not learning this costs. Every deal you underwrite without verifying bank statements, every building you buy without scoping the plumbing, every acquisition where you model 5% turnover because it feels right, you're rolling the dice on a $50,000 to $100,000 surprise. Not if. When. The question is whether you build the framework before that lesson shows up, or after. I built mine after. I'd rather you learn it from reading this than from writing a check.

Looking at a deal in the Omaha or Lincoln market? We'll pressure-test your numbers for free. Reach out at Tanner@TopTierInvestmentFirm.com.

Tanner Sherman is the Principal and Managing Broker of Top Tier Investment Firm in Omaha, Nebraska. He co-hosts the Freedom Fighter Podcast with Ryan of Avara Investments.

What I Learned From My Worst Deal