I don't know for sure if the basement blocks are filled with concrete and rebar, there is no way to access them.

When I initially looked into it, it seemed like it would not be cost effective for C class buildings without fancy key card access points, but maybe something has changed. 

I like the search features: https://www.biggerpockets.com/searchThere are a few self-contained guides that you can access here: https://www.biggerpockets.com/guides

You might also want to check with RHAWA's website, although I believe you need to be a member to access their form resources. 

I plan on airbnb the top floor, right now the entrance to upstairs is inside the house down a long hallway, so I'm going to have steps and a small deck so guests can access from outside.  

"Once that track improvements] happens, 'I can see restaurants, a grocery store and other retail with access to a new park with new athletic fields and a facility that is attractive to the Greater Baltimore community,' Cole said."

If you need more access to capital, I recommend documenting your journey via a blog, social media, youtube, etc.

In our specific case, the appraiser contacted us directly for access to an area that our property mgr has keys.

@Kyle Bunko if all you are looking to do is to get access to the MLS or sell your own deals it’s not worth it.

I really like the alerts feature that can quickly guide you to current topics that may be of interest: http://www.biggerpockets.com/alertsThere are a few self-contained guides that you can access here: https://www.biggerpockets.com/guides