Not that I am any kind of authority by any means, but I read a lot on this site, down loaded a bunch of different plans from Anrew's site:
http://www.angib.pwp.blueyonder.co.uk/t ... tear00.htm , and from all that information, drew a set of plans of my own.
I wanted a certain sized bed, and a certain sized galley, with a certain amount and type of appliances, so there really was no other way.
As far as materials are concerned, I think it is a major storage problem to go and buy all the materials necessary to build the entire trailer, so I purchase what I need to do different phases. So far, it has worked for me, although because my trailer is 5'wide, there is a lot of scrap material left over. Maybe I can have a big bon fire when I'm finished.
