<p>How can that be?</p>
<p>The walls have to be held up by studs of some kind. So even in rooms inside your house there will be 2 slabs of drywall with wood or metal studs inbetween holding them up. I guess this is one reason that in Fla townhouses are considered more desirable. The walls inbetween the units are almost always concrete block in the first and second floors, even if the front and back are concrete block on the first floor, but plywood on the second floor.</p>
<p>I must say tho, in the "duplex" I grew up in (wasn't what they were called then) you could hear it when the neighbors had their grandkids over and they ran back and forth, and those houses, built in the 1890s I think, were SOLID. </p>
<p>Maybe I don't understand what you are trying to say.</p>