Building components of wood, grass and other cellulose material; articles of wood, grass and other cellulose material for building purposes; cladding not of metal for building; flooring, stairs and stairways not of metal for use in buildings; non-metallic building beams; non-metallic building components and materials, including frames, frameworks, facade elements, and kitchen benchtops; non-metallic materials for use in buildings and building decoration; non-metallic modular units for constructing pre-fabricated buildings and building components, including stairways