I’m doing some remodeling/renovating work on a condo in Chicago’s River West district. This location is just outside downtown Chicago and it is considered to be a very desirable. This condo is in a 4 flat that was constructed in 2003, and further the entire interior of the building was gutted and remodeled in 2013. Chicago has strict building codes, and the building’s recent build date would suggest that everything should be top-notch. However, instead I found shoddy construction practices and poor architectural design. Some of the issues could be addressed reasonably, but others will require a major modification of the building and are beyond the scope of my repairs. See the photos below for some examples.

Large patio doors show a beautiful cityscape.
However, when I removed the doors trim it was evident that the installation had never been sealed properly. This allowed water to enter the doorframe and interior. This is a pretty easy fix.
The placement of heating/cooling vents in the ceiling is too close to the windows which caused condensation on the windows and mold problems.
Here you can see some of the mold. This is also an easy fix as all that is needed is a simple duct deflector which will push the hot air away from the cold windows.
A more serious problem was discovered at this window. You can see a lot of rot which I originally thought was due to roofing issues (this unit is on the top floor).
However, I discovered the real problem when I did some exploration in the ceiling. It turns out that the builder never isolated/insulated the heating/cooling vents. The attic space is also not insulated which caused the ducts to become condensation magnets. This was the source of the moisture that damaged the window and is beyond the scope of my repairs. Naturally, I informed the owner of my concerns.
This photos shows how this patch of water damage is in direct line with the heating and cooling vent.