We are both in agreement that our biggest asset is the equity we have stored in these houses-- about $400k.

An odd question, but what would a responsible RE investors consider to be a good % of the value (market price, not equity) of your primary residence compared to their total net worth?  

Yes some of it is their properties have gone up in price to equity, some of it is they have paid some things down, and some of it looks like retirement planning as older more experienced investors move towards retirement and seem to value cash flow over numbers of doors.We personally like moderate leverage, but we are starting to think in terms of slightly fewer doors that are paid off in 15 years vs having as many totally leveraged properties as possible.

I located a great deal on a vacant condemned property that is paid for in full sitting on over $300k in equity.

But after 6-12 months I would like to refinance and pull out some of the equity if I can.

You said "next" so it sounds like you have an asset or two that might have some equity you could use. 

People tapping big into the equity of their primary homes to buy investment property.

Maybe you can get an equity loan on your house or you might apply for a FHA insured loan that helps you get started. 

Ill try to insert a link for analysis if anyone is interested in seeing it, very basic.What I am concerned about regarding finance is it tying up all my funds if I cant refinance to get the equity out within a few years.

My wife and I are looking to house hack as well, hopefully purchasing within the next year and raising our kids (#2 due in november) while building some equity and preparing for future investing.