12 14 and 16 which side panels form support panels and the material can either be applied over the support panels as shown or placed into cavities defined between the support panels and cover panels when the material is applied the cover panels 40 to 50 are pivoted back onto the material and are connected to each other by means of a coiled wire connector such as 18 at the free edges which are shown in fig4 and which meet when the cover panels are placed into position the coiled wire connectors which connect panels 40 and 46 42 and 48 and 44 and 50 may be coupled to the existing coiled wire connectors connecting the structure side panels by the insertion of a connecting rod through the two coiled connectors which are moved sufficiently close so that the coils overlap thereby trapping the surface effect material which is viewable through the panels 40 to 50 as these panels also are of mesh construction the effect is in fact shown in fig6 where the dashed line areas are intended to represent material which in this embodiment is turf so that the wall eventually will have a turf surface appearance this is applied over the whole of the wall surface.