If the building is WF and you just nailed down hardwood over Plywood or OSB, your downstairs neighbor would hear every step you took.2) When you are living in an apartment where people below you can make alterations to their property, you want to compel them to ensure structural changes  won't cause you to become their unintended room-mate.

I must be a market timing wizard since I nailed (I mean to the month) the peak and had to watch my equity grow in the wrong direction for 5 years!

I think @Richard C. hit the nail on the head.  

I think @Andrew Taylor nailed it.  

Awesome, @Kevin Grinstead This is kind of what I suspected, but as with so much in zoning, it's tough to nail down a concrete answer. 

@Andrew Johnson hit the nail on the head.

^ ^ Nick pretty much nailed it.Assuming no deed restrictions...If you sell it to a cash buyer, you can close as quickly as the Title Company can complete their work. 

You guys pretty well hit the nail on the head.

@Natalie Kolodij hits the nail on the head on pretty much every aspect of her post.Your flip is ordinary income, not capital gains.  

Hey @Howard Soon,I think you hit the nail right on the head.