niji architects builds prefab steel house in tokyo using only nuts and bolts niji architects builds prefab steel house in tokyo using only nuts and bolts
jun 11, 2015

niji architects builds prefab steel house in tokyo using only nuts and bolts

niji architects builds prefab steel house in tokyo using only nuts and bolts 
all images courtesy of niji 




light gauged section (LGS) lipped channel is lightweight, easily transported and processed. using the materials distinct qualities, niji architects created the ‘boundary house’. located in tokyo, japan the home is built with steel, but in a way that resembles typical wooden structure construction. in the factory, channels were cut, holes made, and joint hardware fabricated for each connection. once the foundation was completed, prefabricated materials were simply put together — using nuts and bolts exclusively.





the frame was assembled quickly due to the weight of the materials, which was light enough for one builder to carry. due to the load, the foundation didn’t require any pile, meaning that build costs could be reduced even further. the floor, wall, and roof consists of panelling strong and rigid enough to allow for direct fastening, riding the need of backing. steel was left exposed, creating a unique aesthetic in the interior.

niji architects boundary house tokyo designboom
living room  




an eave and balcony were provided according to the client’s need, and like the rest of the structure, attached with nuts and bolts. as a residential project, it differs greatly to the local environment, and represents the homeowner’s flair and personality. the dwelling is flanked on two sides by empty lots. with the nature of future builds totally unknown, niji focused on bringing a strong element of privacy into the plan. windows wrapping the house above and below were carefully placed to create a comfortable, rhythmical living space and tranquil, private bedroom. 

steel framing was left totally exposed 

niji architects boundary house tokyo designboom

hard wood flooring 

exterior at night  

niji architects boundary house tokyo designboom

axonometric drawing


niji architects boundary house tokyo designboom
closs section



project info:


project name: lgs house #01 / boundary house
location: tokyo, japan
building area: 52.85m2
total floor area: 108.28m2
type of construction: steel frame
number of stories: 2
building height: 6.1m
principal use: residence 
project by: niji architects + nichinantekko co.,ltd.
principal designers: masafumi harada, maiko taniguchi 
construction: nichinantekko co.,ltd.
design period: july 2013 – january 2014
construction period: february 2014 – june 2014
photos: masafumi harada



designboom has received this project through its ‘DIY submissions’ feature, which welcomes readers to submit their own work for publication. see more designboom readers submissions here.


edited by: nick brink | designboom

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