It trips off the tongue so easily yet I 'm not so sure its as easy as some imagine to get today's caravans to loose a significant weight by using 'light weight materials'
Now let me set out the challenge with a bit more detail. Take a current production caravan, and replace all the materials you can with light weight versions, but do not compromise the looks, efficiency, functionality, safety, legality or usability in any way.
What components constitute the bulk of the weight of a caravan?
The chassis and wheels
The body, doors/lockers and windows
The internal fixed furniture & fittings
The sink/cooker
The toilet
The space heater
The water heater
The fridge
The battery
The gas cylinders
The caravan mover
The chassis is probably the biggest single element of weight, so it worth looking at that. Alko and BPW have been in the business long enough to know how to make a good trailer chassis. Through testing I am certain both companies will have settled on the best compromise for strength vs weight and cost. They both use folded and pierced steel plate. The other material they will almost certainly have investigated would have been aluminium, but I'm certain that to achieve the same strength and durability using aluminium would require probably as much if not more weight of material. Titanium or carbon fibre composites would almost certainly offer the same performance with a weight saving but the production costs would be many times that of steel.
The second biggest weight element would be the walls and roof etc. It is only in recent years that the manufacturers have looked closely at their construction methods, and the result has been the recent introduction of 'Alu-tech' and 'Solid' construction systems. Both of these claim to have reduced body weight, with some other side benefits. I'm certain the manufacturers will have reviewed in detail the function of the body, to provide weather protection provide rigidity to the whole caravan, to be resistant to water, impact to provide insulation etc, and concluded that they needed the combination and construction of materials to meet all those demands and at an acceptable price point.
The internal fittings, This is where aesthetics have to be considered to a greater extent. It seems that humans generally do have a natural affinity to wood type finish its warm and tactile, in practice wood does have some very fine construction characteristics. It is relatively light weight for its duty as furniture strength, and it can be easily joined. What other material can be formed into a relatively thin and light weight panel that has the same end on resistance to crushing.
And so the analysis goes on and the conclusion I draw is that without some fairly radical design or functional changes to caravans there is not a lot of weight saving to be achieved.
The weight of an average caravan has increased over the years and I suspect this is mainly due to the drive to produce a home from home with all the bells and whistles.
If we want to keep all these features then to achieve any significant weight saving, we need to be prepared to pay a lot more to cover the production costs of specialist materials, or really get the manufactures to start looking at monocoque constrictions to eliminate chassis components or to increase body rigidity with properly stressed panels and shapes.
Alternatively if we are prepared to ditch some of the luxuries, then weights will fall.