As public concern about
global warming rises,
solar and other energy-efficient building
practices are becoming popular throughout much of the
world. With increasing energy prices and
worry over greenhouse gas emissions from
electric power plants, the need for solar, energy-efficient structures has never been greater. Yet
many builders in the U.S. construction industry
have been slow to adopt these new practices.
The pressures on society to conserve energy
and seek more sustainable lifestyles are more
demanding in Japan than in the United States
because of Japan’s high energy costs and limited
resources. Also, many Japanese would prefer
making their buildings more energy efficient
than expanding nuclear energy production,
the predominant energy source for this small
island nation. Consequently, Japan has been
making steady progress with a variety of solar
and energy-efficiency research and construction
One notable research facility is the NEXT21
residential apartment complex, owned by the
Osaka Gas Co. First occupied in 1994, the facility has an ongoing experimental program that
examines innovative energy technologies as
residents live in the building, going about their
daily routines. For an update on the program,
we interviewed Tohru Shiba, manager of the
company’s Planning Technology Team.
The Crumes: Tell us about NEXT21 and
why it was created.
Mr. Shiba: NEXT21 was conceived by the
Osaka Gas Co. to be a model, multiple-unit residential apartment complex for the 21st century.
The goal was to demonstrate that residents could
live comfortably while achieving major energy
savings and minimizing environmental impacts.
The company is concerned about future generations and believes that society must achieve
a harmonious coexistence between humans
and nature. Groups of our employees and their
families have been living at the NEXT21 facility
in five-year cycles, and experimentation with
various energy systems and living configurations has been performed continuously.
The Crumes: What is unique about NEXT21
that has resulted in worldwide attention?
Mr. Shiba: Most Japanese are very concerned about preserving the environment,
reducing waste and leading an economical
lifestyle. Sharing this concern, my company
wanted to build an experimental apartment
complex that would allow testing of advanced
systems designed to reduce energy dependence
and waste. NEXT21 is a largely self-sufficient
facility, where much of its energy demand is
met with fuel cells and photovoltaic panels,
where residential wastes are treated on-site, and
where a green roof provides cooling and insulation. The architectural design, inspired by the
open building concept, will provide maximum
functionality for generations to come. The
name NEX T21 reflects our goal for the building
to maintain its useful lifespan over the next 100
years, through the end of the 21st century.
The Crumes: Explain the open building
Mr. Shiba: This concept was created to provide a flexible response to the changing needs
and preferences of a building’s inhabiants. At
our facility, this is accomplished by separating
the permanent building envelope (that is, the
superstructure or skeleton) from a more adaptable interior (sometimes called the fit-out or
infill). Because service lines are easily accessible behind centralized floor and wall panels,
interior walls can be quickly reconfigured as
the space requirements of our residents change.
Subsystems for electrical, heating, air conditioning and waste management generally function
independently of each other and can be updated
without disturbing other systems. Over time,
changing social, cultural and political conditions affect housing needs — buildings must
be able to adapt to these changing conditions.
Above, the green roof is now home to 21 species
of plants and 22 species of birds. Most of the plants
grew from seeds arriving naturally, borne on the
wind or delivered by birds. Below, the traditional
Japanese bath in a modern environment.