Design center question

I have been messing around with design center and need some clarification.

I live in Condo, technically. I have neighbors on both sides of me. The condo was built 8 years ago and was made with modern construction. This is in the US btw. I know that in condo construction, they have to make it fire rated and put some extra stuff in the walls so if a fire breaks out, it slows the spread. I also know they add some sound absorption insulation in the walls for sound proofing.

With that said, would this be considered a heavy duty wall in design center? Or, would this be considered a standard wall??

Also, I live in a 2 story condo. In design center, I stacked the upper floor on top of the lower floor. I got this part all lined up and squared away. Is there any way to change the floor material? Or, does design center take this into consideration when stacking a second story onto a lower floor? Is there even an option to designate a certain type of floor or how thick it is?

One last question. Is the default attenuation fairly accurate in design center for a certain type of material? For example, a standard wall in design center says it is 4dBm attenuation. Is this failure accurate? Or, should I change yes these values?

Any information would be much appreciated. I am trying to figure out what to get so I can dial in my network and provide coverage for my detached garage. The garage is a black hole and there is absolutely zero coverage in there.

Please and thank you.