Hi, I need to replace an entrance door which is a non-standard size, and so I thought I would have a go at building one from scratch to fit the doorway, as a replacement will be quite costly given it's only a back door to our laundry, and doesn't need to be too pretty. I'm thinking maybe a couple of sheets of plywood fixed to a basic wooden frame? Can anyone provide any information about best materials to use, and/or how to put one together? Many thanks.