MINKA HOUSES

Types of minka

Gassho-style roof

Gassho-zukuri under repair

The term Minka literally means "houses of the people" and it covers houses that accommodated a wide variety of people from farmers through to village headmen, merchants and low level samurai.

Minka come in wide range of styles and sizes, largely as a result of differing geographic and climatic conditions as well as the lifestyle of the inhabitants, but most generally fall into one of four classifications: farmhouses noka town houses machiya, fishermen's dwellings gyoka  and mountain dwellings sanka .

Unlike other forms of Japanese architecture such as those of the sukiya style, it is the structure rather than the plan that is of primary importance to the minka. Minka are divided up with primary posts that form the basic framework and bear the structural load of the building; and secondary posts which are arranged to suit the functional arrangements of the plan.

Despite the wide variety of minka, there are eight basic forms. The inverted U consists of two vertical posts fixed at the top with a horizontal beam, these individual units can then be added together with side girders. The beam can be fixed to the top of the post either by just resting upon it or via a mortise and tenon joint. This latter method is often found in minka on the island of Shikoku. The ladder has a number of post and beam units connected together with larger beams including beams that are closer to the foundation level and this form of structure originated in townhouses of the Edo period. The system will allow the irregular placement of posts and therefore allows flexibility in the plan. With the umbrella style, four beams radiate out from a central post. These posts sit at the centre of the four sides of the square rather than the corners. Minka of this type are often found in Shiga Prefecture. The cross has two beams at right angles to one another with the posts in the centre of the sides. It is often used for very small minka that have no other posts erected within the space, or for large minka in the earth-floored area. The style is most often found in Shiga and Fukui prefectures. Parallel crosses are found in Shizuoka Prefecture and will cover an area 5 metres by 10 metres. This system doubles up the cross structure with two crosses and eight posts. The box structure connects four or more post and beam units to create a box-like structure. It was devised in the Edo period and can be found in Toyama and Ishikawa Prefectures. The interconnected box can be found in Kyoto and Osaka. And finally, rising beams is a form of structure that enables better use of the second storey. It uses beams that rise from the posts to a secondary ridge that is below the one formed by the rafters.

Thatched roof farmhouses based upon the rising beam structure can be further classified into four major types. The first two of these, the yojiro-gumi and the wagoya are rare. Although the latter of these, the wagoya is popular for machiya houses. Far more common are the sasu also known as gasshou  and the odachi types.

The odachi style has rafters, crossbeams and short vertical posts to support the ridge. Historically, these posts would have extended to the ground resulting in a row of posts extending down the centre of the house and dividing it in two. Although these could be accommodated within the layout of the main house, they were impractical within the earth-floored entrance area and so they were omitted and a special beam structure used instead. This style was in wide use until the Edo period when a shift was made to the sasu style although both types had been used since historic times.

The sasu style is a simpler triangular shape with a pair of rafters joined at the top to support the ridge pole. The ends of these rafters were sharpened to fit into mortice holes at either end of crossbeam.

As this system does not rely on central posts it leaves a more unobstructed plan than the odachi style.

Design of the floor plan

Decorative roof projections on the ridge of a thatched roof

There were two main methods for setting out the floor plan of the minka. The kyoma  method uses a standard size of tatami  mat, whereas the inakama method is based upon column spacing.

The kyoma method works well for minka without central columns as the mats and the sliding partitions fusuma  and shoji  can based on a standard size. This method was mainly used in minka in eastern Japan. The method has its disadvantages if used with posts because variations in post width can make the prefabrication of the sliding partitions difficult.

The inakama method is based upon the distance between centre of one post and centre of the post adjacent to it and it was mainly used on the eastern side of Japan.

Overall construction

Tiled udatsu projecting above the roof

The size, construction and decoration of a minka was dependent upon its location and local climate as well as the social status of its owner.

Minka were influenced by local building techniques and were built with materials that were abundant in the immediate locality. For example, minka in Shizuoka used abundant bamboo for roofs, eaves, doors and floors. When miscanthus reeds were difficult to obtain for thatched roofs, shingles were used instead; and in volcanic areas rushes or boards were used instead of clay for the walls.

Climate too had a bearing on construction, in Kyoto in the late Heian and Muromachi periods, roofs were clad in thin wooden shingles so owners would put stones on top to prevent the shingles from flying away in the wind.

The social status of the minka owner was indicated by the size and complexity of the building. For thatched roof minka the number of crossed wooden members umanori  or bundles of miscanthus reeds along the ridge are a good indicator of the importance of the owner's social status within the village. For machiya, the presence and elaborateness of an udatsu, which is a wall that projects above the roof line has a similar status. Latterly the udatsu inherited the function of a fire break, but initially it was a method of establishing the extent of ownership in long terraces of row houses.

During the evolution of minka, the machiya townhouses gradually changed its construction away from perishable and flammable materials to those of a more durable nature. Thatched roofs were replaced with tiles and exposed timbers were covered up with layers of clay plastering.

Minka owned by people of a higher social status began to incorporate elements of the shoin style, particularly within the living rooms. The types of elements incorporated were limited by laws to preserve strict class distinctions.