Insulation.
Big or small, every conversion can benefit from a good core insulation. At the very beginning of the build makes sense, as you don’t want to be moving beds, units and fixtures and fittings about after the fact.
It’s not all about keeping your van warm in the colder months either. As well as keeping you warm, quality insulation will also shield you from the heat in the warmer months. Thermal properties aside, a good thick layer behind all your panels will provide a much quieter and enjoyable driving experience.
Here at SJ Campers we always start with a full coat of silver foil insulation, straight onto the metal, we then fill all voids with a synthetic insulation called Dacron, all topped off and held in place with carpeted ply, made to measure each section of every single van we work on. (The ply doesn’t have to carpeted, but we find it to be a great finish, for most instances, but as always please feel free to contact us direct with any specific requirements.)