During the initial construction, a third unit was built into the half basement with it's own entrance.

There needs to be a switch next to each entrance to the room.Also, receptacles need to follow the 6/12 rule.  

Also, I don't know how your house is setup but if you have a way to offer private entrance, guests tend to prefer these types of properties. 

It is about 20,000 sq ft with a parking lot and about 1.8 acres, all open inside with 4 bathrooms, 4 entrances, it's an old bowling alley (none of that remains, lanes, etc.)

The neighborhoods with entrances off of Votaw and Thompson are all single family homes with values in the $200s to upper $300s or more.   

Custom built because I want to add an inlaw apartment and to design the house in a way where I don't have to interact with the tenants, as in, they have their own exits and entrances and perhaps make their bedrooms into mini studios (with full bathroom and kitchenette).

We would do a single level and finish the basement right off the bat with an entrance directly into the basement.

In other words, there's a main house and an attached Casita (mother-in-law suite) with private entrance and bath.Everyone wants a duplex.

The median home price in San Luis Obispo is currently $707,267 as of today so the barrier to entrance is rather high as well but it is still doable.

The building is stucco and could use a bit of updating to increase rents but overall is in nice shape and entirely rent-ready.It has:- 3 units (2 2 bdrms, and 1 bdrm) all with their own entrance- The 2 bdrms both have their own laundry facilities- Baseboard heat - Ample parking (6 spots)Based on comparable sales there are 2 sales within the last 6 months within about 1-5km from this location that have sold for the following:Duplex with an illegal 3rd unit, all 3 units are 2 bdrms, gas furnace heat - Sold for 340,000 Duplex - 2 bdrms, - Sold for 290,000kBoth of these buildings look nicer than mine on the exterior but mine does not look awful by any means.