It's not as classy as concealed wiring, but it gets the job done.

We are not able to determine the presence or extent of concealed damage.Much thanks,Rich

@Darren Sager I really like split units for the practicality and using the concealed blowers give a really clean look, but not sure why in the USA are that expensive.

In the D neighborhoods the cash flow returns appear greater in theory, but in reality the area will always create additional wear and tear.My solution was to build an enclosure to conceal the exposed water heater, adding "fake" security cameras (real are better but it wasn't in the budget at the time and still did the job).

Maybe concealing the units would appease potential tenants more and an additional shelf or two for storage could be installed too.

Kitchen would be possible, but there isn’t really any way to conceal it?

This is a second floor unit and I believe adding to the issue might be the possibility that the pipe routing contains a concealed pocket ( i.e. floor joist or rim joist area) that has little to no insulation in addition to the draft issue.Any tips on the best way to trace out the pipe routing without entirely removing a large amount of drywall? 

A standing water test is a pretty standard requirement to pass a concealment inspection. 

In any case, it would be extremely difficult for the plumber to separate the supply lines for each unit if they are currently inter-connected and concealed.

The last reason is when you want to conceal from the End Buyer the amount you paid for the property.