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Special Paper Abstract

Japan 2x4 Housing: A Survey of Japanese 2x4 Builders Conducted by the Japanse 2x4 Construction Association.

Translated by Joseph Roos, Edited by Ivan Eastin.   1998. (80pp).  $7.50

The 2x4 construction method developed in North America has excellent performance in areas such as structural safety, insulation, and productivity.

In Japan, houses built using the improved Japanese 2x4 style (based on North American design and construction technology with Japanese design, construction methods and distribution conditions) are in the main stream. In the areas of structural safety and insulation, Japan has reached a level of performance similar to that observed in America. However, in the area of labor productivity there is still much room for improvement.

A number of studies are currently being conducted which focus on 2x4 construction design and construction methods used in North America and the development of appropriate design and building methods for Japan’s hot and humid climate and other natural conditions. From these studies, the basic information required to reach the next step of 2x4 housing will be gained.

1. A study was conducted to identify actual problems that arise when typical 2x4 design and construction methods developed in North America are adopted by Japanese builders. The sample frame for the survey was Japanese companies currently building 2x4 houses.
2. A study was conducted using actual manufacturer’s warranties attached to housing parts and building materials purchased from North American companies in order to better understand the North American warranty philosophy.
3. In order to help define their differences, a comparison of the North American and Japanese 2x4 construction standards was performed.
4. North American-style 2x4 housing design and construction manuals will be developed to promote a smooth introduction and diffusion of North American-style 2x4 building methods.
5. Building methods used in wooden houses located outside of North America will be studied.
6. Experiments will be conducted to determine the fire prevention ability of imported building materials (i.e., wood windows, steel studs, steel joists) to confirm their safety and develop basic safety specifications.

Surveys were sent to 390 companies. Responses were obtained from 145 companies engaged in the construction of 2x4 houses.

The Relatively Early Adoption of 2x4 Construction Methods: Fifty percent of the companies surveyed indicated that they had adopted the 2x4 construction method within six years of the market opening in 1974. By 1985, about 10 years after the opening, over 70% of the companies had adopted the 2x4 method.

Companies Appear that Specialize in North American-style 2x4 Housing: Fifty-six companies (40%) reported experience in North American-style 2x4 housing.. However, of the 2,162 houses built by the survey respondents over a three year period, 1,449 (67%) were built by nine companies and 806 by the top three companies. It would thus appear doubtful that many companies specialize in North American-style 2x4 housing. On the other hand, these results could be interpreted to mean that there is a large number of companies that are not very aggressive in building North American-style 2x4 homes. Small to medium-size companies make up a relatively large part of the North American-style 2x4 construction market, while large companies primarily build regular Japanese-style 2x4 construction.

Currently, Popularity is in the Forefront: The following are reasons provided by respondents regarding their motivation to build North American-style 2x4 houses:

"North American-style 2x4 housing is an area that is going to grow in the future," "they have good qualities that haven’t been seen up till now in Japanese houses" From these examples a positive construction attitude can be seen.

On the other hand, there was also the following dissatisfaction: "there wasn’t as much cost reduction as I had thought" because "workers weren’t used to the 2x4 method," "distribution problems," etc.

When you consider such reasons as "to meet customers’ needs," and "because it is popular," it is apparent that the popularity aspect of North American-style 2x4 housing is ahead of the actual performance advantages. On the other hand, about 60% of the respondents had no 2x4 construction experience. Of these, approximately 40% had negative responses such as "we don’t intend to start," with the smaller companies being more likely to fall into this group. Also, when you consider reasons such as "we don’t know how" and "we looked into it but decided not to follow through" it would seem that some companies aren’t sure how to take up the venture. Approximately 40% of the respondents indicated that they are looking the North American-style 2x4 construction technology. Therefore, there is a possibility that there will be more companies using the North American-style 2x4 construction technology in the future.

Experienced Builders Follow an Aggressive Expansion Trend with the Expectation of Reducing Costs Through Experience: After building North American-style 2x4 houses, 45 companies (83.3%) want to expand further; 5 companies (9.3%) want to stay at the same level. The aggressive companies comprised the largest percentage of the respondents. As the experience level of the company increased, the firms were more likely to expand their construction activities.

The respondents who achieved cost reductions by using the North American construction technology represented only 14.5% of the sample while the respondents that answered "costs weren’t reduced as much as expected" comprised 60%. The reasons given for not achieving cost reductions included: "workers lack of experience" and "productivity did not increase." This area had a high percentage of companies with little actual construction experience. With regard to achieving savings through the use of imported building materials, in spite of the fact that the parts are cheaper, "installation and finishing become very time consuming because of the detailed orders of the home builder." Due to this, productivity is not increased and there is little overall cost reduction.

High Expectations for North American Technology and Materials Introduction: Theoretical cost reductions obtained through using North American construction technology and building materials in Japan consist of reductions in materials costs and in cost for skilled workers. The materials cost reduction effect largely overshadows the reduction of skilled workers effect. The materials cost effect and impacts of factors like deregulation and improved distribution channels can be measured. However, costs for skilled workers can be affected by workers gaining experience, varying customer needs, etc. These can not be as easily measured. Either way, it can be said that there are high hopes for cost reductions based on this theory.

Problems with Construction Certification Plan Preparation, etc.: North American-style housing design and construction plans are sometimes done by foreign architectural firms but most (over 80%) are done in Japan. Over 60% of specifications are prepared in metric measurements, although a large number rely on standard (feet and inches) measure. Certification application plans must be in metric measure. The task of converting measurements is difficult and the use of conversion tools, measurement standardization and other simplification is desirable.

Hope for Official International and Domestic Third-party Organization Role: Package house importing is about 30% of the 2x4 market and thus a small segment of the total market.  In this market segment, there is a relatively high number of companies with little actual construction experience. Construction companies with a lot of construction experience purchase each part separately and then combine them. Ninety percent of the companies importing parts experienced some type of trouble and have concerns about damage, mis-shipments, shortages and extended lead times. It goes without saying that these concerns can be seen most in those companies using the largest volume of products. In order to solve these shipping problems, the development of trust and timely after-sale service are strongly sought. Also, about one half of the respondents indicated they did not understand the handling and service manuals because they were written in English. Manufacturers and exporters need to address this issue to ensure smooth distribution of materials and other benefits.

Regardless of level of experience with North American-style 2x4 housing, cost reductions are expected. Businesses develop aggressively through activities such as investigating or expanding North American 2x4 housing projects. There is the hope for international and domestic third-party organizations to provide service and information related to installation and maintenance of imported parts, trust preservation, and prompt after-sale service.

In this study, we believe the first assessment of North American-style 2x4 housing construction in Japan has been completed. The following main points emerge:

1. The respondents adopted the 2x4 construction method relatively early.
2. Companies specializing in North American-style 2x4 housing construction are appearing.
3. North American-style 2x4 construction has a comparatively large percentage of small companies, while regular Japanese-style 2x4 construction has a comparatively large percentage of big companies.
4. The types of firms building North American-style 2x4 housing range from companies that are consistently building large numbers of homes to companies that are trying the technology on an experimental basis. However, the construction motivation, the appraisal of North American-style, and the handling of problems is very different between these two groups. Generally, companies consistently building a large number of houses handle problems very calmly based on their own previous experience. On the other hand, companies with little actual construction experience seek out help from third-party organizations.
5. Cost reductions from North American-style 2x4 housing are being achieved through consistently building large quantities of houses. Also, regarding the transfer of North American-style 2x4 technology and construction methods as is into Japan, virtually all of the respondents answered they would expect cost reductions.
6. Issues were brought up about problems with delivery, communication, and maintenance of imported North American building materials and it was felt that some type of organized third-party organization is needed.

The Training of Workers in North American-style 2x4 Housing Is Needed: Almost 40% of the respondents indicated that they have some type of regular 2x4 worker training program, and the large companies have regular in-house training. About the same number have some type of training on specifically North American-style 2x4 housing, although almost none have regular in-house training. There methods of training vary so much that no general statement can be made about them. In any case, it would be desirable for a third-party organization to provide a series of widely-available classes.

Lack of Training Becomes a Hindrance To Increased Productivity: The damage from lack of training includes "a lot of man hours," "wasted materials," and project time over-runs become a hindrance to productivity. On the other hand, there is no special attention given to the treatment of workers once they have finished special training.

Tools That Are Used In North America Are Not Used Very Much in Japan: Compared with Japan, a wide variety of tools is used efficiently in North America for 2x4 housing construction. A survey was conducted regarding the recognition level and usability of 14 representative tools. Over 50% of the respondents recognized at least eight of the 14 tools and over 50% of the respondents were using at least four of the 14 tools.

There Is Little Adoption Of The Critical Path Method of Construction Site Management: CPM is effective for grouped construction projects such as subdivisions but is not considered very effective for custom houses. Three companies out of 51 responded that CPM is effective while seven companies indicated they are not going to adopt CPM. Overall, CPM is still in the trial phase.

While it is highly important to consider the future of 2x4 (not limited to North American-style 2x4) housing quality and productivity improvements, the purpose of this study is to develop an understanding of how each company is actually handling the lack of development in worker training. This study was not able to investigate specific details, so it is not able to provide a basis for recommending concrete actions. However, the cultivation and retention of the coming generation of skilled workers is a very important topic that the whole industry needs to consider. Therefore, a continuous and practical study regarding the treatment of skilled workers and other aspects is needed.

According to this study of warranties attached to housing materials imported from North America, it appears that most of these are "limited warranties." Normally, a limited warranty replaces product with manufacturing defects at no charge. Coverage under a limited warranty is only valid when construction is done in accordance with the installation manual and building methods specified by the manufacturer. In addition to the responsibility of the manufacturer, the responsibility of the user is also strongly emphasized.

When redemption of a warranty is attempted from Japan, the procedure for starting a claim is often not known. In many cases, the associated costs such as shipping and construction fees for the replacement are absorbed by the buyer. Another problem is the fees and time needed for shipping (especially with urgent parts, there is no spare time). In order to minimize problems that arise with mis-shipping, etc., learning about the stock of materials is advisable.

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