It is composed of a framework made up entirely of pieces of recycled plastic that basically comprises bearers (1-2), distributed in several sectors along the whole length of the greenhouse and made up of sections (3-4) that are fitted to one another by means of linear connectors (5) which engage on lugs (12-16) and which are in turn joined by means of cross connectors (8) that engage on lugs (17) provided on horizontal sections (6) making up horizontal cross members (7) which brace the framework forming the roof, side walls, front wall and rear wall of the greenhouse. It includes inner spacer clips (23) and intermediate spacer clips (30) that engage on rods (27-27'-27'') securing inner plastic laminar layers (28-28'-28''), between which air chambers are formed that act as thermal insulation for the greenhouse.