I would account for ~$80-$125 per square ft for a GC to handle the construction depending on the level of finish.

Another option is perhaps less attractive but if the money is added to your account over a couple of months and for a couple of months, you wouldn’t have to explain where it came from.

@Henry Der you need to get some legal and accounting advice. 

Accounting for 3 months vacancy, that's $36,000 a year.Is this too good to be true??

Rents are good too, but the cash flow is not so hot after you take into account all your expenses. 

If this is the correct, where do all of you investors account for this charge when running your numbers?  

Shows a decent area in Trulia but income appears to be in mid 30K annually- refer to justicemaps.org.Duplex has both floors rented currently and is cash flow positive at this time.

Do you also allocate a signing fee for new tenants with annual lease etc? 

Major new requirements for short term rentals within city limits as I read it:Pay the city an annual fee ($275 in the first year, $100 o/o, or $125 non o/o in renewal years).Have the resident present during short term rentals.Not rent more than 50% of bedrooms.

Account Closed when you said you used a solo 401k, do you mean you literally cashed out your 401k and paid the penalty then used the cash as the down payment or that you bought the property through the 401k?