However, I am not sure how to approach the current owner. 

For the record, here's my approach when contacting a realtor to ensure that I'm mindful of their time:1.

Hi Cosette,I'm in the wausau area and i know a couple of good realtors but there is definitely a need for a more active boots on the ground approach or solid management here due to weather, condition/age of the properties, and proper screening of tenants(big issue in the area but getting better)If you are serious about getting something in the area definitely do your homework and I might have been through the property already probably and might be able to give some insight.

You, as any appraiser, need to take several approaches and then look at all of them. 

D.C. is quickly becoming a premium market so either you look outside of D.C. or change your approach to be successful in the current market. 

I’ll try to approach my research a little differently and see if there are deals on houses around here and double check to see: “Am I just assuming the above figures are the case, or is really is the case.”I appreciate your viewpoint because I think I would have just gone on assuming without really, really looking at other options.

Market knowledge is your secret sauce the more you know about your market, the key players the properties within the better positioned you will be to move.When it comes to approaching other investors and agents, you have to build that relationship gradually, be involved in the networking events you attend and take part in conversations and try to add value, and soak it all in. 

Some windows need replacement as well and will have an improved thermal rating than the ones from god knows when in the last century.Due to the renovations opening up space to make an HVAC installation more seamless, I have the possibility of taking that approach if the boiler is likely to crap out within the next several years. 

There is a good spreadsheet that Fortune Builders uses and I know that there are calculators online for that approach but I am not sure why converting more than 1 mortgage is advisable.This probably is better discussed in a phone conversation.

Any advice on how should I approach this?