The owner hasn't improved it and Pgh hasn't appreciated that much in two years.

Here is an article that I found on the Veteran's United website because I am trying to do the same thing:https://www.veteransunited.com/valoans/va-rehab-loans/The article states:"Here's what you can do:Repair or add new windows, doors, or sidingRepair or add new roof or guttersInstall new HVAC systems or water heatersImprove insulationWeatherizeTreat mold, lead paint, or moldMake updates to improve energy efficiencyRepair or replace the flooringRepair or replace electrical or plumbing systemsAccessibility updatesIn general, the project has to improve the property's livability and value and must become a permanent part of the home."

To clarify: You mentioned appreciation of $800k But gain will be Calculated as:Sale price <Less> Adjusted basis (purchase price + purchase costs- depreciation)<Less> Improvements you made <Less > Selling costs 

This will help forecast your expected numbers and improve your underwriting skills.I cannot put a price tag on what I learned from this experience.

I am evaluating a few options to improve this situation, one is "status quo" i.e wait another year and then decide since the next rent increase will improve the situation a little, two is to add a detached ADU which I have researched to confirm both feasibility and strong economics, and three is to see about selling the property as a development lot for multifamily, then using the proceeds on another investment. 

Non ad valorem would be taxes that are evenly applied to all properties regardless of value on a per-property basis, commonly for community road improvements, new fire stations, CDD (community development district), or other items like that which impact a small part of the county which those seeing benefit repay over a period of time.

Those exterior type improvements.

Is there a way that I can include a home improvement loan in the rental property calculator? 

@Amer Mallah for instance if you get to a total of 10k for capex, will you keep going or stop there and start over once a huge improvement needs to be made?

I did not raise to market because I was waiting for inherited tenants to leave, make some improvements, then raise rents.