It sounds like the floor in the laundry/maintenance room, kitchen, bathroom and closet with be removed, for sure drywall on 2 walls in maintenance room, most likely 1 wall of cabinets and possibly the other half of kitchen cabinets (lower) and then some carpet will need to be pulled up to help dry out.

Retaining the dollars that you have already made is always a good option. 

When he took a look at it, he mentioned that his advice was to try to rent it as is, and worst case scenario if it doesn’t rent then you have to address putting up a few walls and putting hallways in to separate the bedrooms.

Here are a few key considerations:-Location: A property that is located in a desirable area with good schools, amenities, and public transportation is more likely to attract and retain tenants.

Hi @Petya Toncheva, in my opinion the principal at play here is "best and highest use" and since a room need only have walls and a door to be an office space, but needs to possess more to qualify as a bedroom you're generally better off qualifying it as a bedroom and advertising it however best fits your market.Do be mindful of total square footage and overall utility. 

So, if you buy two units separately with the same 4 walls but two separate mortgages.  

Replaced floors and appliances, painted all the walls.

If you go over 3600 sf you will need to do a fire flow test and depending on the results may need put in sprinklers , although it doesn't sound like you will be getting that big.You need to park both units (duplex or main house+ADU), each unit needs 2 off street parking spaces for a duplex; main house needs 2 but an ADU only needs one and it doesn't need any if it is within 1/4 mile of an Imagine Austin Corridor (Burnet or W Anderson both are I believe).Also a duplex needs to have a shared wall that is at least half the length of the depth of the building (the wall can jog and zigzag, but the total length has to be >.5 of the overall depth front to back of the building).  

The renovation consisted of all new interior and exterior paint, removal of popcorn ceiling, complete floor removal and install, complete kitchen remodel which included a wall removal and converting half of a closet into a pantry, complete master bath remodel, 2/3 remodel on guest bath, All new interior doors and hardware, new front door and hardware, new lighting fixtures, new landscaping, new paint for patio and front sidewalk, and pressure washed driveway.

Every wall, ceiling, floor, appliances inside and out, front and back of all doors, windows, screens, window treatments, lawn from every angle, siding, garage door open and closed, garage floor, driveway, mail box, etc.