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The regional housing system in Japan
HABITATINTL Vol 14. No 2~3, pp 59-62.1990 Prmted m Great Braan
0197-397S/9a$3.00 + 0 00 Pergamon Press plc
The Regional Housing System in Japan The Basic Principles and the Strategies SHUJI FUNO*t and KATSUHIKO OHNOS * Toyo University, Japan and $ Tokyo, Japan
INTRODUCTION
The regional housing systems focused on in this paper, basically mean conventional systems of wooden houses built by local carpenters, contractors and builders. This is not the traditional housing system which existed widely in the region before industrialised housing systems were introduced. The traditional housing systems are partly preserved and are not eliminated entirely. However, they are radically being transformed through the industrialisation process. We have to say regional housing systems are swiftly declining. What does that finally mean? What could be done to reverse the decline and revitalise regional housing systems? These are the questions that I would like to consider and discuss within the Japanese context, in this paper. We cannot go back to the traditional systems, but neither should we consider industrialised housing systems as the only solution. I would like to insist that regional housing systems should be based on the ecological balance in the region. AN OVERVIEW OF HOUSING SYSTEMS IN JAPAN
Japan has about 36 million dwelling units as a stock at the moment. The number of dwelling units exceeds the number of households, but the quality of Japanese housing is so poor that people call it the “rabbit hutch”. To solve the housing problem in Japan, emphasis is placed on improving the quality of houses as well as the living environment. How many dwelling units are newly produced each year? Of course, it differs year by year. Early in the 1960s when pre-fabricated housing systems were not realised, only about 600,000 dwelling units were supplied per year. The number of newly constructed dwelling units continued to increase during the 196Os, that is the decade of high growth of the Japanese economy. The number reached the peak of 1.86 million units in 1973. And then, the number shrank drastically to 1.2 million in 1974 as a result of the oil crisis. All houses in Japan are not necessarily constructed in the same way. We have various systems of production and various types of houses. The proportion of owner-occupied houses in the total number of houses, which was 71.2% in 1958,
t Author Nakanodai,
to whom correspondence should Kujirai, Kawagoe City, Saitama
be addressed at: Faculty Prefecture 350. Japan.
59
of Engmeermg,
Toyo University,
2100
60
Shuli Funo and h’atsuhlko
Ohno
is decreasing. It finally became lower than rented housing in 1985. At the moment, the number of owner-occupied houses more or less equals the number of rented houses. The proportion of detached houses, which was 72% in 1963, is also decreasing (64.8% in 1973,64.4% in 1983 and it recently became lower than other building types, e.g. terrace-house, collective housing etc.). The proportion of owner-occupied houses and detached houses differs region by region. Both are still present in high percentages in the countryside. However. in the metropolitan areas, both are very low. In the Tokyo metropolitan area, the proportion of owner-occupied houses was only 33.0% in 1983, and the proportion of detached houses is only 37.2% in 1983. We have several construction systems. We have a good traditional wooden construction system, and still now, the wooden construction system dominates the whole production of houses. About 70% of the housing stock are wooden houses. On the other hand, the ratio of timber houses newly constructed every year is declining. In 1960, all the houses were constructed by conventional post and beam construction. But several new construction systems were introduced in the early 1960s. Newly built wooden houses were decreasing consistently. At last the proportion of wooden houses in the total of newly constructed houses reached 50% in 1980 and is now less than 50%. The ratio of timber construction depends on regional conditions. It is very high in the north-east part of Honsyu Island, but the ratio of timber structure decreases in the metropolitan belt zone along the Pacific ocean. We cannot supply all the timber ourselves to construct the housing needed, so we have to import more than 50% (65% in 1988) of the timber we need. That is a serious problem for us. On this point, we resemble other developing countries, especially south-east Asian countries. We are responsible for much environmental destruction. Wooden construction systems depend on the supply of timber. If the domestic supply of timber decreases more and more, the wooden construction system will not survive. OR~ANISATION FOR HOUSE PRODUCTION Who or what kinds of organisations produce houses in Japan? How do we classify the suppliers that produce houses in Japan? How many numbers of dwelling units and what kind of house types does each organisation produce? Carpenters (Da&u) cover 60% of the total number of newly constructed houses per annum , 2 x 4 makers covered 1.2% in 1981. Build-and-sell housing suppliers cover 10.4%. General contractors cover approximately 30%. Regional public suppliers cover 7.8%. Prefabricated house makers covered 10.7% in 1981. But the proportion reached 14.4% in 1985 (7.3% in 1973). The proportion of public suppliers is decreasing from 13.1% in 1963 to 5.2% in 1985. We can roughly divide housing organisations into five levels. Huuse
maker
We have 30-40 house makers, several of which produce 50,000 dwelling units a year. The total share of the house makers is 15% at the moment. They have the power to influence the other smafler enterprises. Housing
developer
Build-and-sell housing suppliers develop land and housing estates, then build and sell houses. Their activities cover all of Japan.
The Regional Housing System in Japan
61
Regional house builders
Their bases are located at the regional centres such as capitals of prefectures. They can supply 100-300 dwelling units per year. General contractor Carpenter
Large numbers of dwelling units are supplied by the carpenter and contractor. We have about 160,000 organisations, half of which are carpenters. I later call conventional housing systems in the region maintained by carpenters regional housing systems. Industrialised housing systems and regional housing systems are competitive. There is a relation that regional housing systems decline if industrialised housing systems grow. How to co-ordinate both systems is very important to us.
CONVENTIONAL WOODEN HOUSES As is widely known, the Japanese conventional construction requires a floor plan with a grid of approximately 90 cm module; a unit of two modules is Ken. Walls and openings are arranged according to the module and the grid. The size of a room is described by the number of Tatami mats (each measures 1 x 2 modules), the shorter side being rarely beyond 4 modules. Consequently, the size of pillars can be made within 10.5-12 sq. cm. Walls are thinner than pillars, the latter making openings and others explicitly visible. Among traditional building trades are roofers, plasterers, cloth and paper furnishers, joiners, ornamental metal workers, Tatami mat makers and so on. Each job is done independently with a brief preliminary arrangement, and, if the conventional building custom is observed, creates little trouble at the site. It consists of, in today’s terms, well divided sub-systems; they can also be regarded as open sub-systems, because they are not under a specific total system. The locality of trades also enables the maintenance of houses they built. When building a new house, carpenters assemble regional sub-systems into one total system, but once the house is built, maintenance and repair work are normally done by direct contact with local sub-system trades. Sub-system organisations exist throughout the country and exchange their technologies to co-operate with each other despite some regional differences. This is indeed a very flexible open system which has contributed to the development of traditional wooden houses in Japan. The system had been perfected by the end of the Edo era (the late nineteenth century), and spread widely during the Meiji and Taisho periods (at the beginning of the twentieth century). The system as it was could not, however, meet the requirements of modern society. The fact that it still amounts to almost half of total housing production today proves that it has undergone many stages of structural transformation. As for the exterior finishing, industrially manufactured sidings became commonly used, and with the introduction of aluminum sliding doors for openings, they greatly reduced the labour of carpenters. For roofs too, the industrially produced sheet metal was introduced, but the customers tended to prefer traditional roof-tiles if the budget allowed. Now it is quite clear that the introduction of new materials to Japanese traditional construction has transformed the appearance of houses. As a result, the beautiful vistas of streets that were built in the Edo period have been HA8 14:2/3-e
62
Shu]i Funo and Katsuhrko Ohno
destroyed one after another. The change was so drastic that campaigns for the preservation of the townscape have been set up all over the country. The present Japanese traditional building method that has gone through the period of modernisation differs substantially from the past. The current style described as conventional style wooden houses should therefore be distinguished from the traditional timber houses. It would be better understood if conventional style wooden houses were to be termed ‘prefabricated traditional houses constructed with industrially manufactured materials’, but the term ‘prefabricated’ is a loan word and not suitable to define ‘traditional’ houses!’ REGIONAL
HOUSING SYSTEM
Here I will introduce some projects called HOPE projects (Housing with Proper Environments) which were launched by Ministry of Construction in Japan. Over a hundred local governments have been developing the projects. One of the basic principles of HOPE projects is, in brief, to use as many indigenous materials and products as possible for the benefit of regional industry. I think the spirit of the HOPE project is to create our own landscape, region by region, based on an ecological balance. I have proposed a Kampong Housing System in the context of an Indonesian town .‘,3 I am thinking of the model of regional housing systems in the same way. We can share the basic principles. I proposed the following principles: conservation of the housing community, people’s participation, small scale projects, step by step approach, use of local materials, land sharing systems, etc.
‘cf Yositika Utida. “Building Production in Japan: Its Past, Present and Future”. IOfh Japan-France Budding Colloquu~m. 1988. ‘Shuyl Funo,. “Dominant Issues of Three Typical Kampungs in Surabaya and Conslderatlons in Kampung Housmg System”. Symposium Peran Perbaikan Kamouna Dalam Pembangunan Kota di Indonesra, 1985. ‘Shufi F&o, “Considerations on Housing Systems iase‘h on Ecological Bilance in the Region - Indigenous Houslng System and Self-help Housing In South East Asia”. the 8th Earoph Congress. Jakarta. 1983.
0197-397S/9a$3.00 + 0 00 Pergamon Press plc
The Regional Housing System in Japan The Basic Principles and the Strategies SHUJI FUNO*t and KATSUHIKO OHNOS * Toyo University, Japan and $ Tokyo, Japan
INTRODUCTION
The regional housing systems focused on in this paper, basically mean conventional systems of wooden houses built by local carpenters, contractors and builders. This is not the traditional housing system which existed widely in the region before industrialised housing systems were introduced. The traditional housing systems are partly preserved and are not eliminated entirely. However, they are radically being transformed through the industrialisation process. We have to say regional housing systems are swiftly declining. What does that finally mean? What could be done to reverse the decline and revitalise regional housing systems? These are the questions that I would like to consider and discuss within the Japanese context, in this paper. We cannot go back to the traditional systems, but neither should we consider industrialised housing systems as the only solution. I would like to insist that regional housing systems should be based on the ecological balance in the region. AN OVERVIEW OF HOUSING SYSTEMS IN JAPAN
Japan has about 36 million dwelling units as a stock at the moment. The number of dwelling units exceeds the number of households, but the quality of Japanese housing is so poor that people call it the “rabbit hutch”. To solve the housing problem in Japan, emphasis is placed on improving the quality of houses as well as the living environment. How many dwelling units are newly produced each year? Of course, it differs year by year. Early in the 1960s when pre-fabricated housing systems were not realised, only about 600,000 dwelling units were supplied per year. The number of newly constructed dwelling units continued to increase during the 196Os, that is the decade of high growth of the Japanese economy. The number reached the peak of 1.86 million units in 1973. And then, the number shrank drastically to 1.2 million in 1974 as a result of the oil crisis. All houses in Japan are not necessarily constructed in the same way. We have various systems of production and various types of houses. The proportion of owner-occupied houses in the total number of houses, which was 71.2% in 1958,
t Author Nakanodai,
to whom correspondence should Kujirai, Kawagoe City, Saitama
be addressed at: Faculty Prefecture 350. Japan.
59
of Engmeermg,
Toyo University,
2100
60
Shuli Funo and h’atsuhlko
Ohno
is decreasing. It finally became lower than rented housing in 1985. At the moment, the number of owner-occupied houses more or less equals the number of rented houses. The proportion of detached houses, which was 72% in 1963, is also decreasing (64.8% in 1973,64.4% in 1983 and it recently became lower than other building types, e.g. terrace-house, collective housing etc.). The proportion of owner-occupied houses and detached houses differs region by region. Both are still present in high percentages in the countryside. However. in the metropolitan areas, both are very low. In the Tokyo metropolitan area, the proportion of owner-occupied houses was only 33.0% in 1983, and the proportion of detached houses is only 37.2% in 1983. We have several construction systems. We have a good traditional wooden construction system, and still now, the wooden construction system dominates the whole production of houses. About 70% of the housing stock are wooden houses. On the other hand, the ratio of timber houses newly constructed every year is declining. In 1960, all the houses were constructed by conventional post and beam construction. But several new construction systems were introduced in the early 1960s. Newly built wooden houses were decreasing consistently. At last the proportion of wooden houses in the total of newly constructed houses reached 50% in 1980 and is now less than 50%. The ratio of timber construction depends on regional conditions. It is very high in the north-east part of Honsyu Island, but the ratio of timber structure decreases in the metropolitan belt zone along the Pacific ocean. We cannot supply all the timber ourselves to construct the housing needed, so we have to import more than 50% (65% in 1988) of the timber we need. That is a serious problem for us. On this point, we resemble other developing countries, especially south-east Asian countries. We are responsible for much environmental destruction. Wooden construction systems depend on the supply of timber. If the domestic supply of timber decreases more and more, the wooden construction system will not survive. OR~ANISATION FOR HOUSE PRODUCTION Who or what kinds of organisations produce houses in Japan? How do we classify the suppliers that produce houses in Japan? How many numbers of dwelling units and what kind of house types does each organisation produce? Carpenters (Da&u) cover 60% of the total number of newly constructed houses per annum , 2 x 4 makers covered 1.2% in 1981. Build-and-sell housing suppliers cover 10.4%. General contractors cover approximately 30%. Regional public suppliers cover 7.8%. Prefabricated house makers covered 10.7% in 1981. But the proportion reached 14.4% in 1985 (7.3% in 1973). The proportion of public suppliers is decreasing from 13.1% in 1963 to 5.2% in 1985. We can roughly divide housing organisations into five levels. Huuse
maker
We have 30-40 house makers, several of which produce 50,000 dwelling units a year. The total share of the house makers is 15% at the moment. They have the power to influence the other smafler enterprises. Housing
developer
Build-and-sell housing suppliers develop land and housing estates, then build and sell houses. Their activities cover all of Japan.
The Regional Housing System in Japan
61
Regional house builders
Their bases are located at the regional centres such as capitals of prefectures. They can supply 100-300 dwelling units per year. General contractor Carpenter
Large numbers of dwelling units are supplied by the carpenter and contractor. We have about 160,000 organisations, half of which are carpenters. I later call conventional housing systems in the region maintained by carpenters regional housing systems. Industrialised housing systems and regional housing systems are competitive. There is a relation that regional housing systems decline if industrialised housing systems grow. How to co-ordinate both systems is very important to us.
CONVENTIONAL WOODEN HOUSES As is widely known, the Japanese conventional construction requires a floor plan with a grid of approximately 90 cm module; a unit of two modules is Ken. Walls and openings are arranged according to the module and the grid. The size of a room is described by the number of Tatami mats (each measures 1 x 2 modules), the shorter side being rarely beyond 4 modules. Consequently, the size of pillars can be made within 10.5-12 sq. cm. Walls are thinner than pillars, the latter making openings and others explicitly visible. Among traditional building trades are roofers, plasterers, cloth and paper furnishers, joiners, ornamental metal workers, Tatami mat makers and so on. Each job is done independently with a brief preliminary arrangement, and, if the conventional building custom is observed, creates little trouble at the site. It consists of, in today’s terms, well divided sub-systems; they can also be regarded as open sub-systems, because they are not under a specific total system. The locality of trades also enables the maintenance of houses they built. When building a new house, carpenters assemble regional sub-systems into one total system, but once the house is built, maintenance and repair work are normally done by direct contact with local sub-system trades. Sub-system organisations exist throughout the country and exchange their technologies to co-operate with each other despite some regional differences. This is indeed a very flexible open system which has contributed to the development of traditional wooden houses in Japan. The system had been perfected by the end of the Edo era (the late nineteenth century), and spread widely during the Meiji and Taisho periods (at the beginning of the twentieth century). The system as it was could not, however, meet the requirements of modern society. The fact that it still amounts to almost half of total housing production today proves that it has undergone many stages of structural transformation. As for the exterior finishing, industrially manufactured sidings became commonly used, and with the introduction of aluminum sliding doors for openings, they greatly reduced the labour of carpenters. For roofs too, the industrially produced sheet metal was introduced, but the customers tended to prefer traditional roof-tiles if the budget allowed. Now it is quite clear that the introduction of new materials to Japanese traditional construction has transformed the appearance of houses. As a result, the beautiful vistas of streets that were built in the Edo period have been HA8 14:2/3-e
62
Shu]i Funo and Katsuhrko Ohno
destroyed one after another. The change was so drastic that campaigns for the preservation of the townscape have been set up all over the country. The present Japanese traditional building method that has gone through the period of modernisation differs substantially from the past. The current style described as conventional style wooden houses should therefore be distinguished from the traditional timber houses. It would be better understood if conventional style wooden houses were to be termed ‘prefabricated traditional houses constructed with industrially manufactured materials’, but the term ‘prefabricated’ is a loan word and not suitable to define ‘traditional’ houses!’ REGIONAL
HOUSING SYSTEM
Here I will introduce some projects called HOPE projects (Housing with Proper Environments) which were launched by Ministry of Construction in Japan. Over a hundred local governments have been developing the projects. One of the basic principles of HOPE projects is, in brief, to use as many indigenous materials and products as possible for the benefit of regional industry. I think the spirit of the HOPE project is to create our own landscape, region by region, based on an ecological balance. I have proposed a Kampong Housing System in the context of an Indonesian town .‘,3 I am thinking of the model of regional housing systems in the same way. We can share the basic principles. I proposed the following principles: conservation of the housing community, people’s participation, small scale projects, step by step approach, use of local materials, land sharing systems, etc.
‘cf Yositika Utida. “Building Production in Japan: Its Past, Present and Future”. IOfh Japan-France Budding Colloquu~m. 1988. ‘Shuyl Funo,. “Dominant Issues of Three Typical Kampungs in Surabaya and Conslderatlons in Kampung Housmg System”. Symposium Peran Perbaikan Kamouna Dalam Pembangunan Kota di Indonesra, 1985. ‘Shufi F&o, “Considerations on Housing Systems iase‘h on Ecological Bilance in the Region - Indigenous Houslng System and Self-help Housing In South East Asia”. the 8th Earoph Congress. Jakarta. 1983.