I would drop it to about 18 inches, that way you can get better air flow for flame combustion and you do not restrict the heat it gives off.  

The wind tore down her pool cage and the storm water flooded her older home (and car) several inches. 

im thinking for a one square inch of a postcard or letter why not.

I'm a welder by trade so I built a 4 inch deposit  pole it's buried about 3 feet in the ground so they can't steal it they insert the money thru a hole in pipe and above ground level I made a section of pipe that comes out with a stain less steel  security  lock on back side  pretty much any box with lock would work  attached  to property just make  sure they don't put cash  or it might just disapear

This all goes much deeper than the three inches below the surface where inexperienced real estate operators/investors frolic along with W.

The tenant pool, however, is about 5 miles wide and 1 inch deep. 

What you are referring to is the difference between going a mile wide and an inch deep, or going an inch wide and a mile deep... 

I renovated every single inch of this property.

A small 18 inch square would suffice, then you can just patch that section. 

Dishwasher,  Many people won't have a lot of pots for the cabinets but everyone will have dirty dishes for the dishwasher.  24 inch DW tends to be cheaper but if you have to go with an 18 it is still worth it.