CONTENTS

JAPANESE TALES

Sekisui House - Japan.

A RECENT TOUR OF JAPAN STRETCHED THE KNOWN POSSIBILITIES OF OFFSITE CONSTRUCTION, MANUFACTURED HOUSING AND ENVIRONMENTAL AWARENESS, WRITES FRASER PAXTON.

We landed into a steamy Narita airport (Tokyo) at about 7pm on a Sunday night in July. A small inquisitive group of people from around the world was gathering for the annual ZEMCH Mission to Japan.

ZEMCH, stands for Zero Energy Mass Custom Homes, and is the brain child of Associate Professor Masa Noguchi of the University of Melbourne. The expedition has become an annual pilgrimage for anyone wanting to see the advances in offsite construction in Japan. Needless to say, the country that gave birth to lean manufacturing and everything that comes with it didn’t disappoint in offsite construction. The schedule was packed full of visits to universities, research labs, and of course house manufacturers. Of these were Misawa Homes, Sekisui House, Sekisui Heim, Daiwa House, Hebel Haus, and the University of Tokyo.

“The expedition has become an annual pilgrimage for anyone wanting to see the advances in offsite construction in Japan. Needless to say, the country that gave birth to lean manufacturing and everything that comes with it didn’t disappoint in offsite construction.”
Fraser Paxton.

The level of sophistication in these factories was worlds ahead. As just one example, the house energy management systems (HEMS) presented at Tokyo University had been refined to the point of balancing out the energy used through the entire home. The energy usage information of the house is broken down to include zones, appliances, and the car (which is electric), and is neatly displayed on the television, enhancing occupants’ awareness of energy use.

This is essentially a growing extension of the Internet of Things. Simply put, appliances, windows and blinds for solar control, are connected to the HEMS. The effect, for example, is that if the thermostat is set to a certain temperature then the HEMS has the capability to open or close both blinds and windows to passively heat or cool the house.

From a design point of view, the manufactured houses were nothing but beautifully crafted and considered pieces of architecture. The staggering thing was though, that they were created in a factory, within a framework of standard components.

“From a design point of view, the manufactured houses were nothing but beautifully crafted and considered pieces of architecture. The staggering thing was though, that they were created in a factory, within a framework of standard components.”

Sekisui House had a structural system of perforated steel girders that could be arranged in an infinite number or permutations to suit a customer’s needs. Much of their work was completed on site, as a house would arrive in kit form and be assembled with the speed you would expect from such a process.

Sekisui Heim however, created houses on a moving production line, where a house would be composed of 10 or 11 ‘volumes’. These volumes were steel or timber framed, and from start to finish took approximately six hours to complete, with one being finished every five minutes on the line.

Sub assembly components such as stair and kitchens were moved off the line, then fed back in at the appropriate time to complete the package that would be sent to site. This puts the house manufacture process at around eight hours, from start to finish, with customisation included. Foundations on site are prepared using a form liner for the footings, achieving millimetre precision with anchor plates that receive and lock the modules in place. Once on site, a house takes one day to complete.

The emphasis on user experience in the procurement stage of a customer’s house buying process was also striking. Imagine walking into a showroom the size of IKEA and having all of the possible variations for flooring, kitchen, bathroom, every fixture and fitting you have in a house available in front of you to look touch and hold, and to assemble in to the form of the house you want.

Misawa Homes took this one level further, having created environments to fully showcase their products’ functionality. Windows were displayed so their performance could be experienced. Misawa had assembled two rooms next to each other with a passage around them that was spatially independent and cooled to four degrees. One had ordinary glazing and window frames, the other had thermally broken frames with low e double glazing. Prospective clients were able to enter each room to experience the temperature in each, superior windows obviously providing a warmer room.

Earthquakes are of course a common occurrence in Japan, and most manufacturers had a simulator, which prospective clients could enter to experience how the particular types of dampers, bracing and materials performed, up to an 8.3 magnitude quake in one case. One manufacturer went as far as to demonstrate the fire performance of their Hebel cladding, conducting a live fire test in front of us. It got better when you could hold your hands against the other side of the all to feel the insulating effect of Hebel against three blowtorches at full throttle pointing at the wall.

A government requirement for all new houses to be passive by 2020 has put pressure on housing companies to develop solutions for the past 10 years, and they have been quietly achieving great results. Solar roof tiles have been on the market in Japan since 2003, and as such are common. Clever materials such as unglazed porcelain are also used in more humid climates, where an entire wall clad in it can help to reduce the humidity in the room as the porcelain sucks up moisture.

“A government requirement for all new houses to be passive by 2020 has put pressure on housing companies to develop solutions for the past 10 years, and they have been quietly achieving great results. Solar roof tiles have been on the market in Japan since 2003, and as such are common. Clever materials such as unglazed porcelain are also used in more humid climates, where an entire wall clad in it can help to reduce the humidity in the room as the porcelain sucks up moisture.”

The ZEMCH Mission to Japan is not one to forget. For a true sense of the definition of advanced manufacture of offsite construction, it’s a must. Advances in Japanese processes, methods, materials, and attitudes towards better quality housing are truly inspiring. Australian practitioners would certainly benefit from taking many of these up in the pursuit of better housing for everyone.

The ZEMCH Mission to Japan 2017 took place from 24 to 28 July, 2017. The tour is organised by Dr Masa Noguchi, Associate Professor in Environmental Design at the Faculty of Architecture, Building and Planning, University of Melbourne.■

Fraser Paxton is currently working on an MPhil leading to a PhD researching the ‘Design for lean manufacture of low cost housing’ at CAMP-H – Melbourne University. His self-named architecture practice has also developed a modular housing solution using structural insulated panels (SIPs).

 

 

 

 


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