Once my door was at this stage and was ready to UV I had to check that it worked properly and didn't have any problems with hidden faces inside the model or any accidental extra vertexes.
In order to check this quickly I exported my whole door as an object file and opened it in Mudbox. When you try to subdivide an object in Mudbox that has hidden faces or five sided shapes it will tell you and won't be able to subdivide.
I did this and found several hidden faces and vertexes. I think the mistake I made was when I deleted edges sometimes I forgot to delete the vertexes at the end of them. If you don't delete the vertexes then programs will still read them and it will expect an edge to be there and will read this as a polygon with more than four sides. Polygons with more than four sides cannot be subdivided easily or equally and therefore need to be avoided.
Some tools I found useful at this stage were the append to polygon tool and the merge vertex tool.
The append to polygon tool is useful for rebuilding faces where there aren't enough edges to use the fill hole tool. For example I found that I needed to rebuild the edge of my door. I planned to not have it there as it wasn't going to be seen but because of the way my door geometry was made up I needed to put it back in to prevent having vertexes with no edges attached along the top curve of the door. I didn't want to just delete them as I would lose the shape. I thought by having vertexes it would count as a four sided shape but I didn't really realise you can't have a vertex that isn't attached to an edge.
by selecting the tool and the clicking on the corners of the face you want to rebuild it should appear.
Press enter and the face will appear. I carried on around the edge of the door until it was all rebuilt.
The merge vertex tool is useful when you have an extra vertex and want to merge it with one that is near it.
Simply click the first vertex and hold and drag to the other vertex, let go and they should merge into one.
