Converting Archimesh to standard Blender objects

I initially used Archimesh to create a house plan, including windows. I have since decided that these are difficult to manipulate and have gone back to using native Blender tools. However, some of the windows are as I want them visually so I decided to remove these from the WIndow Groups (that Archimesh assigns) and use these as individual objects.

One thing I noticed was that these could not be manipulated in Object mode (such as rotate, move, scale, etc) and I could only carry out these actions in Edit mode, with the whole mesh selected.

Has anybody else come across a situation where objects are not behaving as objects in this way? And if so, can these be converted into correct Objects? I have tried convert to mesh but this did not change how they behaved.