Before the development of greenhouses, agricultural practices were constrained to weather conditions. According to the climatic zone of communities, people were limited to a select range of species and time of the year in which they could grow plants. Yet around 30 CE, the Roman Empire built the first recorded attempt of an artificial environment. Due to emperor Tiberius’s declining health, the royal physicians recommended that the emperor eat one cucumber a day. Cucumbers, however, are quite tender plants and do not grow easily year-round. Therefore, the Romans designed an artificial environment, like a greenhouse, to have cucumbers available for the emperor all year. Cucumbers were planted in wheeled carts which were put in the sun daily, then taken inside to keep them warm at night. The cucumbers were stored under frames or in cucumber houses glazed with either oiled cloth known as specularia or with sheets of selenite (a.k.a. lapis specularis), according to the description by Pliny the Elder.
The next biggest breakthrough in greenhouse design came from Korea in the 15th century during the Joseon dynasty. In the 1450s, Soon ui Jeon described the first artificially heated greenhouse in his manuscript called Sangayorok. Soon ui Jeon was a physician to the royal family, and Sangayorok was intended to provide the nobility with important agricultural and housekeeping knowledge. Within the section of agricultural techniques, Soon ui Jeon wrote how to build a greenhouse that was able to cultivate vegetables and other plants in the winter. The Korean design adds an ondol system to the structure. An ondol is a Korean heating system used in domestic spaces, which runs a flue pipe from a heat source underneath the flooring. In addition to the ondol, a cauldron filled with water was also heated to create steam and increase the temperature and humidity in the greenhouse. These Korean greenhouses were the first active greenhouses that controlled temperature, rather than only relying on energy from the sun. The design still included passive heating methods, such as semi-transparent oiled hanji windows to capture light and cob walls to retain heat, but the furnace provided extra control over the artificial environment. The Annals of the Joseon Dynasty confirm that greenhouse-like structures incorporating ondol were constructed to provide heat for mandarin orange trees during the winter of 1438.