Most real estate deals don’t fail because of comps

Most bad real estate deals don’t fail because of comps.

They fail because investors underestimate execution risk.

On paper:
- the ARV works
- the spread looks attractive
- the neighborhood seems strong

But then:
- permits take longer
- insurance changes the numbers
- slope/foundation issues appear
- rehab budgets expand
- layout limitations reduce upside
- liquidity weakens during exit

A lot of investment tools focus heavily on pricing data and comparable sales.

But the more we study real-world projects, the more it seems that the real challenge is understanding the relationship between:

acquisition price  
market positioning  
renovation complexity  
timeline risk  
and actual execution feasibility.

Especially in value-add and redevelopment scenarios.

Curious how experienced investors here evaluate this side of deals today.

What part of underwriting do you think is still the hardest to model accurately?