After yesterdays optomistic post, the solution I had posted hadn’t worked. For some reason because I was trying to create splines on the elevation and then extrude them into plan 3ds max was not happy. So the wonderful solution I had found did not work. I’m not sure why as I’m fairly sure that it wasn’t a problem with the first window I created. But i have found a work around. I had to draw my first spline then rotate it through 90 degrees then draw a new spline over the top which would then allow me to extrude it. I could then rotate this newly extruded spline back through 90 degrees to be in the right position. At this point I thought it would be easy to just taper the window, not so. Because of the mucking around with rotating it would not taper in the right way so I had to go through a series of messing around with tapers to find the right combination of axis (while knowing the effect I wanted in what appeared to be the correct axis). I found that using this method I need to taper primary: z and effect: y for 0.51.
But now I have the start of window made. I am now going to try to use it to cut out the window from the walls.