3871 Solid timber structural systems (0) Proprietary solid timber structural systems or part systems 3872 Glue laminated timber and CLT structural systems (0) Proprietary glue laminated and cross laminated (CLT) timber structural systems or part systems 3873 Plywood and LVL structural systems (7) Proprietary plywood or laminated veneer lumber (LVL) timber structural systems or part systems 3874 Wood fibre and strand based timber structural systems (1) Proprietary wood fibre or wood strand based (oriented or non-orientated), boards or sectional timber structural systems or part systems 3876 Structural Insulated Panel Systems (SIPS) (0) Proprietary structural prefabricated timber framed sandwich panels, consisting of two outer skins of timber based boards, usually with an internal core of insulation. 3877 Composite engineered wood structural systems (4) Proprietary composite engineered wood structural systems or part systems, using more than one type of engineered timber, or engineered timber with solid timber components.