@Christian Wathne, our tiny homes are configured to use regular RV hookups.  

The Code acknowledges that certain dwellings may be configured to allow a third person to comfortably sleep in non-bedroom space, and that infants and very young children can share their parents' room."

The biggest factor is what the market will bare as a sales price for  the same configuration (SFR 3/2 or MFU of 8 2/1). 

I have built a % for vacancies and repairs into my formula for configuring ROI.

The 1/1 configurations tend toward higher vacancies as these are typical singles which tend to be more mobile. 

The other 4plex that sold was very similar except that it was 2 above 2 below configuration.  

about 10-15k depending on how the house is configured.

Our target rental neighborhood has mostly 2/1's, so we seek out other configurations to set ourselves apart, and prefer 3/1's and 3/2's.  

Online review “Prolog is relatively easy to deploy, and the cost for a small company to implement the system would be in the range of $10,000 for three concurrent licenses and another $10,000-15,000 for implementation and basic configuration” Landlord Maxx - Aaron Saarela said, “We just started Landlord Maxx which was 199.00 one time fee.

This is NOT to say that the rental market is not still super strong, but it is not the crazy insane rental market we've seen recently.For example, here are rents by week for single family homes in Fort Collins (all bedroom configurations).Also, when we run our analysis numbers, we still recommend (and use) 3% for vacancy and strongly recommend investors start looking for tenants at least 60 days prior to your current lease expiring.