Keep your square footage low to minimize expenses.New construction is not necessarily the answer.

You may need to develop additional funding sources and take on larger rehab projects, higher price points and (.atvleast for me) target deals where you can force appreciate by adding square footage, increasing bed or bath counts, and reconfiguring layouts.

It's also good for finding the year builts, square footage, etc.I don't know why the KC-area realtors treat the MLS like a big secret. 

Once you know the type of roof & square footage & the approximate age of the heaters you can then use a site like Homewyse to calculate local costs to replace.  

Using comparable square footage,  compare the ones with redone kitchens and baths to ones in the same neighborhood with old kitchens and baths.  

Maybe looking at the improvement value of a few recent sales and dividing by the number of units to get a "per unit" replacement cost, then doing the same for the land portion of the comps and dividing by the land square footage to get a $/sf land value. 

Current rents in my area for my sq footage is $450 above what my mortgage is.

You can also search for liens, accurate square footage, etc. directly on the cities site. 

Given that square footage and location are fixed what can an investor improve that will raise the appraisal the most?  

In addition to the pricing, taxes and square footage ect.