I'm pretty sure that the cost to get this done is not cheap!

Depending on location they can cost a lot to replace but when you factor in what you save from paying sewer bills it’s cheaper in long run.It would not stop me from buying a house

Can try to reposition to Class B, but neighborhood may impede these efforts.Vacancy Est: Historically 10%, but 15-20% should be used to also cover tenant nonpayment, eviction costs & damages.Tenant Pool: majority will have FICO scores of 560-620, many blemishes, but should have no evictions in last 2 years.

That is a lot of negative cash flow.Adding the ADU will have cost and effort but should improve the negative.  

After researching, we found that converting a single-family home into a duplex could cost around $200-300k.

It cost us $3,000 to demo the shower and retile it.

Shawn - I would suggest you develop a pro forma based on the stabilized state of the property to understand if it cash flows once all units are occupied being sure to include all reasonable revenue assumptions (rents, vacancy factor, etc..) as well as expenses (debt payments, maintenance, utilities, property management, taxes, insurance, turnover costs, etc..)

Right now we pay our cleaner $300 per turn but charge guests $250.The costs of having a STR about an hour outside of town.

Pushes the cost of damage protection insurance onto the hosts and guests.

I will recover this cost of new heating equipment in 2 years through the savings of what I paid this year for heating oil.