If you are strictly looking for maximum appraisal value then perhaps consider it if you can develop/finish the attic space well below the $314 $/ft average for a 5 bedroom.However, other factors you may want to consider are increased operational costs (e.g. heating, cooling, etc) that will stay with you well past the cash out refi.

Should I wait to purchase a. Investment property to see if prices come down or buy now because interest rates are lower?  Which will be less expensive in the long run, higher price now vs possiblehigher rate down the ...

I had just completed a full rehab in 21213 and decided to throw an OLD window a/c unit upstairs to keep the place cool while I was away for a week.

Their virtual world is really cool though! 

A heating and cooling contractor should be familiar with these; plumbers will probably be as well.

Oh cool I’ve never heard of those pre fab ADU’s!  

Cool will do @Sam Issa, what kind of investing do you do in Boca Raton?

As for the AC & Furnace I would suggest buying a thermostat lock box; buy a smart thermostat that can switch from heat to cool on its own; set it and forget it.

Should I vote to change the heating/cooling to an HVAC system?

I still have a lot to learn, but it is cool to know that other people my age are making it happen right now.