the floor panels engages a corresponding groove 124 on an adjacent floor panel in an interlocking relationship this relationship prevents the floor panels from separating from each other during assembly of the enclosure and afterwards the tabs 122 and recesses 124 also allow the panels to be connected to each other without the use of additional fasteners floor panels 102 also include a plurality of apertures 126 spaced around the perimeter of the panel the apertures are adapted to receive fasteners 128 therein the fasteners 128 are secured to a structure 129 beneath the floor panels the structure can be a concrete slab a wooden structure a plastic structure a composite stricture etc in an illustrated embodiment in fig4 an l bolt is illustrated as the fastener 128 the l bolt is secure to the structure 129 with a speed nut 130 the l bolt then passes through aperture 126 and is secured to the panel 102 with a nut 132 in addition to l bolts other fasteners such as bolts screws nails etc can be employed to secure the floor panels to an underlying support structure left wall assembly 200 is assembled prior to being secured to floor panels 102 as illustrated in fig5 a plurality of vertical members 208 are secured onto the bottom plate 202 in the precut slots 204 with fasteners not shown a top plate.