Exploring MUJI HOUSE's Zero Infrastructure Homes for Sustainable Living

MUJI HOUSE Co., Ltd. is embarking on an ambitious project to develop a trailer house that can operate independently of existing utilities, capable of self-sustaining energy production. This initiative, named the "Zero Project," began in March of last year, aiming for practical application by 2025. In April of this year, they unveiled the prototype to the press. So, what exactly is this "house"?

Solar Power and Water Circulation System

The prototype consists of two units: a utility unit and a living unit, both made of wood, each covering approximately 12 square meters.

The utility unit is immediately noticeable for its integrated solar panel roof and walls. This design enables electricity generation even during the low-sun conditions of early morning or winter. For a two-person household, the system can store up to three days' worth of electricity, with the storage capacity viewable via a smartphone. The solar panels are made from durable silicon materials.

Inside the utility unit, on the left, there is a kitchen area equipped with an IH cooking heater, sink, refrigerator, microwave, and kettle. On the right, there is a hot water shower, and at the back, a water circulation system. This system purifies and recycles wastewater, capable of handling up to 200 liters of water per day, sufficient for a two-person household. Electricity for cooking and showering comes from the solar panels, while the water used is purified through the water circulation system.

The kitchen in the utility unit utilizes solar-generated electricity for the IH cooking heater, microwave, and kettle. The water used is purified and recycled by the water circulation system.

The utility unit also includes a hot water shower, using an electric heat pump water heater (EcoCute) powered by solar-generated electricity.

Decomposition of Waste by Microorganisms

Moving to the living unit, on a rainy and slightly chilly day, the first thing noticed upon entering was the warmth. The insulation, 90mm thick in the walls and floor and 60mm thick in the roof, provides high thermal efficiency. According to Koji Kawauchi, the company's Executive Director of Product Development and Project Leader, staff members have tested the prototype since November last year and found that on sunny days, heating isn't necessary even in winter.

The living unit also features a solar panel roof. Inside, it includes two mattresses, an air conditioner, lighting, a mini-fridge, batteries, and a bio-toilet. Although drinking water needs to be brought in, the amenities are otherwise sufficient for comfortable living.

The bio-toilet uses sawdust and microorganisms to decompose waste, including human excrement, food scraps, and toilet paper. The microorganisms are kept active with electricity that maintains the internal temperature at around 40 degrees Celsius. The toilet can handle up to 20 uses per day, adequate for a two-person household. The sink uses a simple automatic faucet system that pumps water from a portable tank.

Challenges: Energy Storage During Bad Weather and Compact Water Circulation System

Currently, the project is soliciting feedback from participants who stay in the prototype. The second term of trial stays begins on May 31 (until June 23). Some challenges have already been identified.

One significant issue is energy storage. Simulations suggest that the prototype works well as a weekend retreat, but even the largest batteries struggle during three consecutive rainy days. To address this, the second prototype will include provisions for external electricity sources, such as electric vehicles or generators, to charge the batteries.

Another challenge is the size of the water circulation system, which occupies about two-thirds of the 12-square-meter utility unit. Kawauchi aims to refine and compact the system, reducing costs and improving maintenance.

Ultimate Goal: Self-Sustaining Community

Kawauchi explains that the Zero Project aims to bring a rich daily life to places with sparse infrastructure, providing a viable living option for various demographics, including the elderly and young children. The project also addresses issues like vacant houses, aging rural infrastructure, and frequent natural disasters, aiming to create a sustainable living environment resilient to these challenges.

He envisions a community where the self-sufficient "Zero House" serves as a central hub, providing water and electricity to surrounding homes. This model promotes mutual support and a return to a simpler, community-focused lifestyle, which might be the key to a brighter future.

Japan's infrastructure, much of which was developed during its period of rapid economic growth, is now aging. According to the Ministry of Land, Infrastructure, Transport and Tourism, by March 2030, 55% of road bridges, 36% of tunnels, 23% of river management facilities, 16% of sewage pipes, and 43% of port facilities will be over 50 years old. By March 2040, these figures will rise to 75%, 53%, 38%, 35%, and 66%, respectively.

Addressing this issue is urgent, but budget constraints and labor shortages complicate the task. The insights gained from the Zero Project's practical application could potentially contribute to solving these problems. The progress of this project and MUJI HOUSE's challenge will continue to attract attention.MUJI HOUSE Co., Ltd. is embarking on an ambitious project to develop a trailer house that can operate independently of existing utilities, capable of self-sustaining energy production. This initiative, named the "Zero Project," began in March of last year, aiming for practical application by 2025. In April of this year, they unveiled the prototype to the press. So, what exactly is this "house"?

Solar Power and Water Circulation System

The prototype consists of two units: a utility unit and a living unit, both made of wood, each covering approximately 12 square meters.

The utility unit is immediately noticeable for its integrated solar panel roof and walls. This design enables electricity generation even during the low-sun conditions of early morning or winter. For a two-person household, the system can store up to three days' worth of electricity, with the storage capacity viewable via a smartphone. The solar panels are made from durable silicon materials.

Inside the utility unit, on the left, there is a kitchen area equipped with an IH cooking heater, sink, refrigerator, microwave, and kettle. On the right, there is a hot water shower, and at the back, a water circulation system. This system purifies and recycles wastewater, capable of handling up to 200 liters of water per day, sufficient for a two-person household. Electricity for cooking and showering comes from the solar panels, while the water used is purified through the water circulation system.

The kitchen in the utility unit utilizes solar-generated electricity for the IH cooking heater, microwave, and kettle. The water used is purified and recycled by the water circulation system.

The utility unit also includes a hot water shower, using an electric heat pump water heater (EcoCute) powered by solar-generated electricity.

Decomposition of Waste by Microorganisms

Moving to the living unit, on a rainy and slightly chilly day, the first thing noticed upon entering was the warmth. The insulation, 90mm thick in the walls and floor and 60mm thick in the roof, provides high thermal efficiency. According to Koji Kawauchi, the company's Executive Director of Product Development and Project Leader, staff members have tested the prototype since November last year and found that on sunny days, heating isn't necessary even in winter.

The living unit also features a solar panel roof. Inside, it includes two mattresses, an air conditioner, lighting, a mini-fridge, batteries, and a bio-toilet. Although drinking water needs to be brought in, the amenities are otherwise sufficient for comfortable living.

The bio-toilet uses sawdust and microorganisms to decompose waste, including human excrement, food scraps, and toilet paper. The microorganisms are kept active with electricity that maintains the internal temperature at around 40 degrees Celsius. The toilet can handle up to 20 uses per day, adequate for a two-person household. The sink uses a simple automatic faucet system that pumps water from a portable tank.

Challenges: Energy Storage During Bad Weather and Compact Water Circulation System

Currently, the project is soliciting feedback from participants who stay in the prototype. The second term of trial stays begins on May 31 (until June 23). Some challenges have already been identified.

One significant issue is energy storage. Simulations suggest that the prototype works well as a weekend retreat, but even the largest batteries struggle during three consecutive rainy days. To address this, the second prototype will include provisions for external electricity sources, such as electric vehicles or generators, to charge the batteries.

Another challenge is the size of the water circulation system, which occupies about two-thirds of the 12-square-meter utility unit. Kawauchi aims to refine and compact the system, reducing costs and improving maintenance.

Ultimate Goal: Self-Sustaining Community

Kawauchi explains that the Zero Project aims to bring a rich daily life to places with sparse infrastructure, providing a viable living option for various demographics, including the elderly and young children. The project also addresses issues like vacant houses, aging rural infrastructure, and frequent natural disasters, aiming to create a sustainable living environment resilient to these challenges.

He envisions a community where the self-sufficient "Zero House" serves as a central hub, providing water and electricity to surrounding homes. This model promotes mutual support and a return to a simpler, community-focused lifestyle, which might be the key to a brighter future.

Japan's infrastructure, much of which was developed during its period of rapid economic growth, is now aging. According to the Ministry of Land, Infrastructure, Transport and Tourism, by March 2030, 55% of road bridges, 36% of tunnels, 23% of river management facilities, 16% of sewage pipes, and 43% of port facilities will be over 50 years old. By March 2040, these figures will rise to 75%, 53%, 38%, 35%, and 66%, respectively.

Addressing this issue is urgent, but budget constraints and labor shortages complicate the task. The insights gained from the Zero Project's practical application could potentially contribute to solving these problems. The progress of this project and MUJI HOUSE's challenge will continue to attract attention.