Abstract: A modular building panel comprising a rectangular frame 11 having one face covered in a water resistant board 16 with the other face also covered in a board material 17, the frame having top and bottom rails 12, 13 joined together by wood composite “I” beams 14. Two of said I beams 14A & 14B also form the sides of the frame with their recessed sides 28 facing outwardly thereof. The recessed sides 28 of the outer I beams 14A 14B in use accommodate jointing posts for linking adjacent panels.

Abstract: A wooden composite “I” Beam 10 comprising upper and lower plywood flanges 11,12 interconnected by a web 13 comprising a pair of widely spaced apart planar side walls 25 26 formed from wood or wood derivative material. The cavity formed within the web 13 is filled with a core of cellular material 17 corrugated cardboard or paper which is adhered to the side walls and flanges using adhesive resin.