Two apartments separated by secured door?

[Joseph C.]

Hello everyone! We had a situation that we are curious if anyone has seen or heard of before. Any feedback would be appreciated!

There is a 2 unit property for sale that we recently looked at. Side by side units, 3 bedrooms on each side. What is unique about this property is that the large front living room on each side has been converted to studio apartments by adding a full bath and kitchenette. This leaves a 2 bedroom apartment on each side as well. In essence, there are now 4 units. Because the area is zoned single family residential and 2 family, it was accomplished by keeping a secured door between each unit (each studio and 2 bedroom). The utilities were not split, as there is a furnace and hot water heater per side. Utilities are included in each rent.

Does this situation sound appropriate? It presents as a savy way to increase cash flow by finding a loophole in the building code that allows for this...almost a renting out rooms separately situation. On the other hand, one could argue that it is indeed now a 4 unit. 

Not sure if anyone has heard of a situation like this. Quite honestly, it presents as an attractive option for us...just looking for information prior to getting serious. Thank you in advance for any feedback!