http://www.caravantalk.co.uk/community/topic/91805-timberless/page-1
http://www.practicalcaravan.com/forum/buyers-guide-caravans/new-upmarket-swift
Same idea as Alutech but using no nails similar to Eldiss. But with a 5 layer no wood floor.
Vans are over 20K and are a little heavy.