Open Panels- these are structurally engineered panels that form the i side load bearing leaf of the external wall. Comprises of studs, rails, sheathing and a breather membrane to external face. I stalled using pretreated softwood timber for which a sheet of OSB or ply is fixed.
Closed Panels- faster to erect on site, made from studs, rails, and insulation with sheathing and or liners on the faces of the panels. They also incorporate a breather membrane external face. The walls, floors and roofs are delivered fully fabricated ready for installation on site. These are far heavier to manoeuvre. These are an excellent choice in the UK due to the reliance of the weather conditions.