5 Deal Analysis Mistakes That Cost Investors Thousands
Deal Analysis

5 Deal Analysis Mistakes That Cost Investors Thousands

Marcus Webb·Founder, RealEstateInvestorHQ
6 min read
July 14, 2026

Even experienced investors fall into these analytical traps. Avoid these five common errors and protect your returns before you ever close a deal.

Underwriting is where deals are won or lost — not at the closing table. Here are the five analytical mistakes I see most often, even from investors with multiple properties under their belt.

1. Using the seller's pro forma. Sellers present best-case scenarios. Always build your own model from actual rent rolls, trailing 12-month operating statements, and independent market comps. Never underwrite to projected rents you haven't verified.

2. Underestimating vacancy. A 0% vacancy assumption is fantasy. Use market vacancy rates (typically 5–10% for residential, 8–15% for commercial) and stress-test your model at 20% vacancy to understand downside risk.

3. Ignoring capital expenditure reserves. Every property needs a CapEx reserve — typically $100–200/unit/year for residential, or 5–10% of NOI for commercial. Skipping this line item inflates your returns on paper and destroys them in practice.

4. Forgetting closing costs and carry. Transaction costs (typically 2–5% of purchase price), holding costs during renovation, and financing fees all reduce your effective return. Model them in from day one.

5. Anchoring to purchase price instead of value. Your job is to buy below intrinsic value, not to justify a price you've already emotionally committed to. If the numbers don't work at the asking price, walk away. There's always another deal.

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Marcus Webb

Founder, RealEstateInvestorHQ

Real estate investor, educator, and founder of RealEstateInvestorHQ. Helping investors at every level build wealth through disciplined, data-driven investing.

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