property conversion analysis (first post)

[Eduardo Rodriguez]

Hello BP community, so I have been lurking for a few weeks at all the posting and advice on the forums and have finally convinced myself that in order to maximize earning potential on a property I have been holding for a few years now I will have to convert it into a multiplex. the details are as follows:

• currently, owe 120K @ 4.7% 
• 6300 sf ranch style SFR, it is built on two residential lots (room to add a duplex adjacent to this property)
• currently brings in $1650 for rent, have rented out as high as $2000 (the Eagle Ford shale was booming a couple years ago)
• have been slowly upgrading and improving (new roof, new laminate flooring, some lighting fixtures, new paint)
• needs to be updated this was built in 1990, windows are old, some of the siding looks weathered and the worst part is the bathrooms are dated (everything is functional)
• I have looked at housing rents and most 2/1 or 2/2  usually command $900-$1300
• Appartments are a little bit cheapper $700-$1100

I had trouble using the rental estimator calculator, then tried the BRRRR, I linked the report estimating the following:

https://www.biggerpockets.com/calculators/shared/1083149/4f695ede-d602-47bf-a183-b0d69ff0cf64

• Upgrading showers 
• adding new back porch deck (for access to upper units)
• converting where two new upstairs rental units would have a kitchen, 2 baths, and 2 bedrooms (comparable to an apartment) about 800 sf ($ 1200 per unit)
• lower dwelling 3000 sf could be split as well or rent out @ 1500 (would update and add one more full bath) making it 3/2 and 1/2 very large dwelling
• All bills paid (water, sewer, power, lawn maint) about 1K per month

Please review and point out flaws, mistakes were made but so far all on paper and in process of cash out refi, to pay for this conversion. so far budgeted $65K. advice appreciated. more details as required