BRRRR, improve units or add unit.

[Victor Longinotti]

We are doing a cash out on one property to purchase another. We are a self-employed family buying rentals on the side to hold. The current property we are looking at buying a triplex.  This house has some room for improvement in a few ways but I have a specific question about which path we should take, we have about 50K to invest in this property before doing another cash-out.  As I said there is room to improve the units and house with new paint, some general repairs, appliances in the units, floor, bathroom updates.  HOWEVER, there is also a huge two car garage that could be turned into a 1-2 bedroom unit grossing $1200-$1500 monthly.  If I am thinking in terms of getting my down payment back to invest in another property then which of those scenarios may work best?  I am thinking the new units add more value if I am looking to sell to another investor, but if I am just looking to refinance for more value will an appraiser see that as an improvement to increase the value of the home, or will the other general improvements get me that increase.  Any input is greatly appreciated, we can also get the property for around $500k in an extremely strong rental market.