We have a sun room built by a contractor for which building plans had to be approved by the city and a professional engineer. The room is about 12' x 12' and attached to the house. It sits on a wooden box frame on top of 4 ground anchors that sit in heavy, heavy clay.
Five years after construction one of the windows has lost it's seal and there is a point of movement between two drywall sheets. I patched the area between the two drywall sheets but a week later the crack is back!
I believe that the ground anchors are moving just a little bit due to the clay and the temperature range of -40 deg F to + 90 deg F range that we get in a year.
It's too late to do anything with the anchors as they are boxed in. There is siding covering the exterior of the box and wire mesh from there to the ground to keep animals out.
Is there anything that can be done for the drywall or a new window that would tolerate slight movements?
From the pictures it looks like they put in two ground screws and then attached the box to the concrete foundation of the house.