The plan is to build an entrance in the back that would lead directly into the basement/apartment.

It came with a detached studio (500 sq ft with a bathroom) - the studio has a separate entrance, private yard. 

It's a small bedroom and under normal circumstances such bedrooms are charged as if the tenant would be sharing a bathroom and a kitchen with other tenants also sharing a room, while also using a shared entrance. 

They may have an automatic gated entrance, but no guard on duty or staff on site.

Usually a finished basement with a separate entrance.

It had two entrances, good ceiling heights, etc. 

You may be able to get lucky with a duplex, but at least in the NoVa area it’s a lot more common to have a basement with a separate entrance and turn it into a studio of sorts to approximate a duplex.

In order to convert the basement into a legal secondary dwelling unit, some cities require a separate entrance to the exterior, the HVAC to be separated from the rest of the house, the bedrooms must have opening windows of sufficient size to qualify as a means of egress.

The basement unit, with it's own entrance, is ideal for someone looking to house hack, and have the greatest privacy.With these changes, not that costly, believe your rents while not as much as 3 legal apartments, but wouldn't be that much less.

At the end of the day I'm sure your teacher has the greatest intentions for you and the rest of the class to have a strong entrance into investing and the work force in whatever capacity you see fit.