A system or kit of wood and plastic component materials is provided which can readily be assembled to form a structure. The components are precut so that measurement and cutting of the component materials is eliminated. The components are readily assembled using conventional fasteners. Components have precut notches in order to facilitate the assembly of the components without the requirement for measurements. This assures that the components will be assembled correctly and eliminates the opportunity for inaccurate measurements. The roof is formed from plastic panels secured to wooden trusses. The floor is formed from plastic panels secured to the wood framing of the walls. The plastic roof panels and plastic floor panels are designed to be secured to each other and to the wood frames to assure heavy duty interlocking construction of the components.