Examples of Our Value Creation Model
Example [3] Building Renovation

Renovating an urban high-rise building without
rebuilding and strengthening community functions
Key issues for Nishi-shinjuku, an urban business area

Wide-ranging functions are highlyconcentrated in the area. However, large
subdivisions and double-layered
roadways obstruct continuity andmovement and disperse interaction.

Created “Sankaku
Hiroba,” one of thelargest atrium
spaces in Japan
Upgraded facilities
to the same level
as those of a newbuildingServes as a local disaster preparedness center in emergencies
Serves as a temporary evacuation facility for around 2,800 people unable toreturn to their homes
A model for sustainability of a high-rise building withoutrebuilding• Enhanced BCP functionality (damping reinforcement, emergency powergenerator)• Reduced environmental impact (installed energy-saving equipment
equivalent to new-building standards)• Eliminated uneven flooring (facilitating barrier-free movement)■ Shinjuku’s new hub for liveliness
The Nishi-shinjuku district, where Shinjuku Sumitomo Building is located, was designated a subcenterof Tokyo in 1958. Since then, it is not only a business center where approximately 200,000 people
work but also an area where there is a high concentration of a variety of functions, including large
hotels, commercial facilities, universities, hospitals and residences. On the other hand, as the district
was developed on a former water purification plant, it faced some issues such as open spaces
representing 80% of the district’s areas and a two-layered structure of roads obstructing the continuity
and movement of the cityscape and dispersing vibrancy. The Sankaku Hiroba project is a major publicprivate project to enhance the function of the district as a whole, beyond a single building. It isexpected to bring about a new vibrancy to the district by hosting a variety of events in one of thelargest all-weather event spaces in Japan with a capacity of about 2,000 people and taking advantageof the adjoining Shinjuku Sumitomo Hall, which is equipped to host international conferences.

A view of an event held at Sankaku Hiroba■ Counter-disaster facility for the district
In 2011, while the project was underway, the Great East Japan Earthquake inflicted unprecedented
damage to areas across Japan. As the damage highlighted the importance of disaster prevention inurban areas, we designed Sankaku Hiroba so that it can shelter temporarily up to about 2,800
stranded commuters in the event of an emergency. Furthermore, in the remodeling work to the mainbuilding, we enhanced measures for business continuity planning (BCP) for the further safety oftenants including seismic reinforcement and expansion of oil tanks and generators.

We implemented an extensive renovation of Shinjuku Sumitomo
Building, an office-use skyscraper originally completed in 1974, andin July 2020, we completed the “Sankaku Hiroba” (triangular plaza),a large space for public events. Sankaku Hiroba is an all-weather
atrium of approximately 3,250m2 created by building a gigantic glass
roof over an open public space incorporated into the building’s
design. The facility not just adds to the vibrancy of the Shinjuku
district, where wide-ranging functions are highly concentrated, but
provides a disaster prevention function as an emergency shelter incase of large-scale disasters. Having been renovated instead ofrebuilding, it serves as a model embodying how an office building canachieve sustainability.

Chronology
Completed Construction of Shinjuku Sumitomo Building

2016

Designated as a national strategic special zone; city planning of specified district changed

2020■ A model embodying sustainability of office buildings

BeforeCross-section of Sankaku Hiroba
Shinjuku Sumitomo
Building*Approx.

1974
2017

Sankaku Hiroba, one of the largest all-weather event spaces in Japan

Started Large-scale renovation – certified private-sector city revitalization project plan
Completed Large-scale renovation work – Opened “Sankaku Hiroba”
Gross floor area: 180,195m2 Atrium area: 6,500m2* (Sankaku Hiroba: 3,250m2*)

25m

Sankaku Hiroba
Shinjuku Sumitomo Hall(22 m effective height)

Shop & Restaurant

Shinjuku Sumitomo Building has been adored by the public and nicknamed “Sankaku Biru” (triangularbuilding) for its shape for nearly half a century since 1974 in a period when skyscrapers started to bebuilt in Japan. Instead of tearing down the Sankaku Biru, the project created a sophisticated interior
space as fresh as a newly constructed building through extensive remodeling work, which introduced
cutting-edge equipment and designs but left the triangular outward appearance intact. By choosing
not to tear down and reconstruct the building, we significantly reduced the amount of industrial waste,such as construction materials, and by introducing energy-saving equipment on a par with those fornew buildings, we reduced the environmental load. Furthermore, the remodeled building entrancesenhance the barrier-free feature of the region by designing pedestrian routes that resolve height gaps
in surrounding areas.

■ CTBUH* Awards: The first in Japan to win the “Award of Excellence” for the Renovation Category
This renovation project of Shinjuku Sumitomo Building was recognized for its innovative approach and excellence as well as its applicability to other projects and thehigh quality attained in the following areas: ”Environment” – it minimize effects on the natural environment, ”People” – it has a positive effect on the inhabitants
and the quality of human lives, ”Community” – it demonstrates relevance to the contemporary and future needs of the community in which it is located, and”Economic” – adds economic vitality to its occupants, owner and community. The project became the first to be awarded the “Award of Excellence” in the CTBUH
Awards 2021/Renovation Category by the CTBUH.
*The CTBUH (Council on Tall Buildings and Urban Habitat) was founded in 1969. Its goal is to increase global understanding of tall buildings and sustainable urban housing and develop expertise through international
interchange between experts, in order to create healthy urban environments.