Apartment to AirBnB to Condo Conversion

[Loren Miner]

Here is a healthy modern day brainbuster. I am currently underwriting the following play -

Currently a 25-50 unit multi-family. Primetime location. No shortage of traffic. 

Renovated each unit

Convert to full-time Airbnb 

Exit plan - year #6 sell as condo conversion 

*Keeping it slightly vague for privacy purposes*

MY QUESTIONS - 

What vacancy rate do you run for short-term rentals? Has anyone run a large scale Airbnb? 

Expenses of condo conversions? 

Any other pitfalls I may be missing? 

I have done a fair amount of research on the subject, but feel the community would enjoy the challenge as it is not common practice!