Series: What is Supervision? Part 2
A group of supervising engineers takes on the challenge,
Improving construction quality and streamlining construction processes

What are the benefits of having an architectural firm oversee construction? — Kei Kohinata, Senior Member of the Construction Supervision Group Director(At the time of the interview)He explains, “We can provide construction supervision that benefits the client by accurately understanding the designer’s intent and taking the contractor’s technical capabilities into account.”
On construction sites—where various stakeholders are involved from design through completion—construction supervision by an architectural firm involves ensuring the quality of the building by applying specialized expertise and maintaining a neutral, third-party perspective.

At Nikken Sekkei, we define the “role of construction supervision” as the following four elements.

In Japan, there is a cultural tradition of not including too many details in design drawings, leaving it up to the contractors to determine the specific construction methods. While this practice reflects respect for the contractors’ technical skills and creativity, it requires them to thoroughly interpret the designer’s intent as expressed in the drawings and accurately reflect it in the construction drawings. At the same time, they must verify that the quality and functionality specified in the design documents are consistent with the construction drawings.

Once the construction drawings are complete, we must review the construction methods. This is a process of collaborating with the contractor to determine the procedures that will ensure functionality and quality while enabling the construction work to proceed smoothly. To prevent defects in areas that will become hidden as construction progresses, we review construction plans, construction guidelines, and factory fabrication instructions at various stages of the construction process and conduct repeated inspections of the construction methods.

During inspections conducted both during and after construction, we verify that functionality and quality meet design specifications. If any defects are discovered at this stage, it can lead to rework or delays in the construction schedule, causing disadvantages for all parties involved. “To prevent this from happening in the first place, we need to focus on steps ① and ②,” said Senior Kohinata. Director(At the time of the interview). Nikken Sekkei’s construction supervision safeguards the client’s interests by assessing the precision of the work from a perspective different from that of the contractor.

Items ① through ③ fall within the scope of construction supervision as defined by the Building Standards Act; however, at Nikken Sekkei, we also consider providing advice to contractors regarding construction operations to be part of our supervision services.Construction management refers to “management at a construction site involving numerous stakeholders—including the client, designers, contractors, and manufacturers—that goes beyond mere construction planning and execution,” according to Senior Partner Kohinata. Director(At the time of the interview)I'll explain.

He explains the secret to putting this into practice by citing a management principle that has been passed down within the company: “Seventy percent planning, thirty percent skill.” “A supervisor who can effectively manage a job site has a solid plan in place. They don’t just think about tomorrow or next week—they have a clear vision of the entire process leading up to completion.”

Here, “skill” refers to technical knowledge, such as checking construction drawings and conducting construction inspections.On the other hand, “planning” refers to “sharing a common understanding and resolving issues early on with contractors and other stakeholders.” For example, in rebar work, reviewing the intent of the structural drawings and the rebar installation guidelines with the contractor and discussing the procedures in advance ensures that on-site operations run smoothly. Kohinata Senior Director(At the time of the interview)He says, “The true appeal of construction supervision lies in earning the trust of those on-site and serving as a hub that ensures the work of all stakeholders proceeds smoothly.”

Nikken Sekkei aims to ensure quality while also streamlining, improving the efficiency of, and facilitating the construction process by having project managers implement these four elements in a well-balanced manner.
 

Starting from the conceptual design phase, we establish appropriate construction schedules and evaluate constructability, providing phased support tailored to the level of detail and precision required for the project. For example, in large-scale urban development projects involving underground excavation, the construction schedule has a significant impact on the budget. By conducting technical assessments of the client’s interests and risks from the earliest stages, we incorporate these findings into the design to proactively prevent cost overruns and schedule delays.

For projects with a high level of construction complexity, members of the Construction Technology Support Office sometimes join the design team from the early stages and even give presentations to the client.
Regarding the Shibuya Station area redevelopment project, for which Nikken Sekkei provided consulting services, and the “Shibuya Scramble Square the First Phase (East Tower)” (2019), for which the firm served as design supervisor, Senior Partner Kohinata stated that various challenges—including complex underground construction, construction on a narrow site, and the reorganization of passenger flow—were “overcome through a three-way collaboration among the developer, the contractor, and the design supervisor.” Director(At the time of the interview)He says that such specialized skills will be put to use in future projects—such as redevelopment—that require advanced expertise.

Design drawings must take constructability into account. We are working to improve the robustness of our design drawings to prevent design changes caused by poor constructability, as well as the resulting problems such as increased costs and extended construction schedules.

The Construction Engineering Department also provides technical consulting services commissioned directly by clients, including proposals for construction plans for the redevelopment of large shopping centers and the design of special structures for massive underground shopping malls in front of train stations.
 

As an independent third party separate from the design, supervision, and construction teams, we provide effective and appropriate advice to ensure reliable quality and the smooth progress of construction projects, thereby supporting building owners. The Construction Technology Department is a group of experts that transcends internal and external boundaries to provide technical support for a wide range of challenges—from planning through design and construction to post-completion.

In our next post, we’ll discuss sustainable organizational management.