A hanok is a traditional Korean house. Hanok were first designed and built in the 14th century during the Joseon Dynasty.
Korean architecture considers the positioning of the house in relation to its surroundings, with thought given to the land and seasons. The interior of the house is also planned accordingly. This principle is called baesanimsu, meaning that the ideal house is built with a mountain in the back and a river in the front. Hanok shapes differ by region. In the cold northern regions of Korea, hanoks are built in a square with a courtyard in the middle in order to retain heat better. In the south, hanoks are more open and L-shaped.
The environment-friendly aspects of traditional Korean houses range from the structure's inner layout to the building materials which were used. Another unique feature of traditional houses is their special design for cooling the interior in summer and heating the interior in winter.
Since Korea has hot summers and cold winters, the 'Ondol (Gudeul),' a floor-based heating system, and 'Daecheong,' a cool wooden-floor style hall were devised long ago to help Koreans survive the frigid winters and to block sunlight during summer. These primitive types of heating and air-conditioning were so effective that they are still in use in many homes today. The posts, or 'Daedulbo' are not inserted into the ground, but are fitted into the cornerstones to keep Hanok safe from earthquakes.
The raw materials used in Hanok, such as soil, timber, and rock, are all natural and recyclable and do not cause pollution. Hanok's have their own tiled roofs, wooden beams and stone-block construction. Cheoma is the edge of Hanok's curvy roofs. The lengths of the Cheoma can be adjusted to control the amount of sunlight that enters the house. Hanji is lubricated with bean oil making it waterproof and polished. Windows and doors made with Hanji are beautiful and breathable.
The structure of Hanok is also classified according to social class. Typically the houses of yangban (upper class), Jungin (middle class) and urban commoners with giwa (tiled roof) emphasized not only the function of the house, but also possessed great aesthetic value. On the other hand, the houses of the provincial commoners (as well as some impoverished yangban) with choga (a roof plaited by rice straw) were built in a more strictly functional manner.