Hoklartherm Riga S GreenhouseHoklartherm Riga S Greenhouse The Riga s is a great choice for gardeners who need a year round greenhouse that fits in a compact space. As the smallest of the Riga line it is both shorter and narrower than other Riga models, and is available in several different lengths. It features 8mm twin wall polycarbonate glazing panels on its side walls and slightly thicker 10mm panels on its ends, making it extremely insulative. Like all Riga models, its sloped