I recently had an inspection ins a well-to-do suburb, north of Chicago. The house was originally built in 1915 and was remodeled and added to in 1999. After the addition, the house was about 4,500 SF, with an added 2nd floor and an added floor over the attached garage. A really nice house, at first glance, and selling for more that 1 Mil.
When the house was remodeled, the house was sided with Exterior Insulation Finishing System (EIFS). There are many manufacturers of this product and many fine installations I have seen. But I have also seen many installations that were done by unqualified contractors. Keep in mind that this work was inspected by the local building code inspectors and passed.
On the south side of the house, the EIFS framing around the window was not properly sealed against water leaking behind the wall covering.
When viewed with Thermal Imaging, this water infiltration is clearly seen (the purple area on the left side and under the window). Radio Frequency moisture scanning further verified this problem.
The window frames were also not properly flashed and water had gotten behind the EIFS and was causing blistering. Moisture readings taken on the exterior, and on the interior walls, were in the 30 - 35% range. When wood moisture readings exceed 19%, wood rot begins and mold can form behind the walls.
When the chimney was extended, it was not done by professional masons, but only by people hired out of the local home improvement store parking lot.
The new attic was not properly ventilated (ridge vent nailed down too tight and soffit vents covered with insulation) which has lead to high moisture levels in the roof decking (55 - 60%), rotting of the roof deck plywood and mold formation. The 2nd floor bathroom exhaust fan vents were also not properly vented to the exterior, futher increasing the moisture levels in the attic.
In short, because the owners chose to hire the lowest bidding contractor, did not have the work inspected (by a home inspector) and did not do their own due dillegence, the deal fell through and the owners will now have to either disclose these problems or have them fixed. Since the contractor they hired was not insured (Errors and Omissions Insurance is a critical factor), this will be a big expense to them.
Welcome to the world of a home inspector.