A CHANGING SOCIETY
Japanese society is changing. People are
living longer and having fewer children, more
women are in the workforce, and single-per-son households are increasing in number, as
are singles living with roommates.
When housing needs change, NEX T21’s
flexible floor plan allows room dimensions
and utilities to be easily reconfigured. For
example, an apartment occupied by a family
of four may someday be needed by a working
couple or single older adult requiring less
space. Because pipes, conduits and ducts
are located in centralized vertical shafts and
between floors, separate from the building
superstructure, changing the size and layout
of a NEXT21 apartment is easy.
Interior layout can
easily be adapted to the
lifestyle of the tenant.
CLICK: View a slide show: solartoday.org/NEXT21
the basement. Here, waste materials are broken
down in a wet catalytic oxidation reactor, resulting in a relatively clean exhaust gas (mainly CO
2
and nitrogen), reclaimed water and waste heat.
Waste water from the kitchen, bath and toilet are
treated in a contact aerating biological treatment
system. Some of the waste water from these processes is piped to an activated carbon treatment
system and then used as grey water in toilets and
for watering plants. Garbage like aluminum cans
and plastics are recycled by the municipality.
native to this region of Japan, the survival rate
was not good. Yet today there are 21 different
plant species on the roof that are thriving but
were not originally planted — they arrived
naturally as seeds carried by birds or with the
wind. Now that the plants have been established, at least 22 species of birds frequent the
roof. Counting the rooftop garden, courtyard,
terraces and plant zones outside the building,
we have about 10,800 square feet (1,000 square
meters) of green space. No matter where you are
As society changes, so must its buildings.
The Crumes: What are some of the other solar
and energy efficiency features of the facility?
Mr. Shiba: In addition to the photovoltaic
cells, the exterior walls have a high insulating
value, and the windows are relatively small. A
very important feature is the green roof, which
provides both insulation and evapotranspira-tional cooling for the roof-top as well as a nice
urban garden area for residents to visit. The soil
depth there is about 3. 3 feet (1 meter).
The Crumes: We have noticed a lot of
greenery up there. Was it hard to get the green
roof established?
Mr. Shiba: This is an interesting story.
Although we initially planted species that were
in the complex, you see green.
The Crumes: How well does your building
perform in reducing energy consumption and
helping the environment?
Mr. Shiba: Compared with a conventional
building outfitted with ordinary insulating materials and a standard central air conditioning system, our facility is about 30 percent more efficient. Emissions to the atmosphere of CO , the
2
principal global warming gas, are also reduced
by around 30 percent, and emissions of another
important air pollutant, nitrogen oxides, are cut
by about 75 percent. Because trees remove CO
2
from the air, the facility’s reduced CO emissions
2
can be related to the number of trees that would
have to be planted to achieve the same reduction
— this number is about 5,000 trees every year. In
addition to reducing the amount of waste generated, our waste processing system decreases tap
water consumption by about 20 percent.
The Crumes: Are there any other technologies to tell us about?
Mr. Shiba:Wherever possible, we used the
latest technologies for reducing energy waste.
One example is our sophisticated energy control system that anticipates demand and balances
energy use throughout the day. In the apartments, we installed innovative appliances, such
as an automatic self-cleaning bathtub that sprays
a detergent and water mix under high pressure,
and a range top equipped with steam cleaning
wands. Also, energy monitors in the apartments
display consumption, allowing residents to make
lifestyle changes to reduce their energy needs.
To further improve the quality of life, we tried
to use natural materials and finishes and to eliminate things like plywood that may have undesirable off-gassing properties.
The Crumes: We have learned a great deal
about new energy technologies for residential
apartment units in Japan.
Mr. Shiba: Thank you. NEXT21 is an ongoing research program that has yielded important results on new technologies and lifestyles
and will continue doing so for years to come. As
society changes, so must its buildings. ST
