1. What Is an Architect's Main Job? Creating Design Documents, Not Just Buildings
When building a house, carpenters do not start cutting wood immediately. First, there must be a plan that decides the shape and materials. In Japan, the Architects Act calls these plans and specifications "design documents." The law states that an architect’s first main duty is to create these documents under their own responsibility, which is called "design" [1].
The second main duty is "construction supervision." The law explains this as checking the construction work against the design documents to see if it is being done correctly [1]. So the law treats drawing the plans and checking the work as two distinct duties of architects. This leads to an important question: why is construction supervision a second duty?
2. Why Does an Architect's Name Appear on a Drawing? To Show Responsibility
Think about a school test. You write your name so the teacher knows the answers are yours. Architectural drawings work similarly. The Architects Act requires an architect who carries out a design to state on the design documents that they are an architect, and to sign them [1].
Drawings are the foundation for buildings that may last for decades. It is meaningful to know exactly who took responsibility for drawing them. If a problem or question comes up, the drawing shows who took responsibility for the design. However, even perfect drawings are useless if the construction team builds something different on site. This is why the second duty, construction supervision, becomes essential.
3. What Does an Architect Do at the Construction Site? Acting for the Client
The people who actually build the structure are the contractors. The person who asked for the building is called the "client" (or building owner). The architect doing the supervision is neither the contractor nor the client. They check the work from the client's standpoint.
The Tokyo Metropolitan Government explains that construction supervision means checking the work against the design documents from the standpoint of the client, to confirm it is being done as planned [2]. The standard tasks include four things: communicating the design intent to the contractors, checking and approving construction drawings to ensure they match the design documents, confirming the physical work matches the drawings, and submitting a supervision report to the client [2].
If the architect finds work that differs from the drawings, the law has a rule. The architect must immediately tell the contractor and ask them to fix it according to the design documents. If the contractor does not comply, the architect must report this to the client [1]. Checking the site against the design documents is how a gap between the paper plans and the real site gets noticed. Also, for certain buildings, the Building Standards Act requires appointing a supervisor, and the status of supervision is written in the applications for intermediate and final inspections [2].
4. How Do the Three Architect Licenses Differ? By the Building's Size
Not all architects have the same license. There are three types in Japan: First-Class, Second-Class, and Wooden Architect. First-Class architects are licensed by the Minister of Land, Infrastructure, Transport and Tourism. Second-Class and Wooden architects are licensed by prefectural governors [1].
What each architect can do depends on a combination of the building's use, structure, total floor area, and number of stories. For example, buildings used by many people, like schools, hospitals, theaters, and department stores, require a First-Class architect if they exceed a certain size. Even for wooden buildings, if the height or number of stories is large, a First-Class architect is needed [1].
On the other hand, for new wooden buildings with a total floor area above a certain size, First-Class, Second-Class, and Wooden architects can all do the design and supervision. However, because the rules depend on a combination of factors, it is dangerous to memorize a single number like "under X square meters." The specific limits are set out in the law. One way to read these rules is that mistakes in larger buildings used by many people may have a greater impact. The law itself does not state this as the reason, so treat it as an interpretation.
5. How Hard Is the First-Class Architect Exam? Only About 1 in 9 Passed in 2025
Becoming a First-Class architect is difficult. The exam has two stages: a written exam and a design/drafting exam. According to the Ministry of Land, Infrastructure, Transport and Tourism, in 2025 (Reiwa 7), 27,489 people took the written exam on July 27. Only 4,529 passed, which is a pass rate of 16.5%. For the design/drafting exam on October 12, 11,381 people took it, and 3,988 passed, a rate of 35.0% [3].
It is important not to mix these numbers up. The 35.0% is the pass rate for the drafting exam only, among those who already passed the first hurdle of the written exam. If you count from the very beginning to the end, the overall pass rate was 11.4% (out of 35,127 total candidates). This means about 11 out of 100 people passed [3].
The 16.5% and 35.0% rates are for separate stages and cannot be multiplied into one number. Because only people who passed the written exam can take the drafting exam, 35.0% is a share within a selected group. It is a mistake to read it as "one in three people passes the First-Class exam."
6. Why Was the Architects Act Created in 1950? To Rebuild Cities
The Architects Act was promulgated on May 24, 1950 (Showa 25), and came into effect in July of the same year. It was created by legislators. The background was the urgent need to rebuild cities damaged by war. At that time, there was no qualification system for engineers to handle design and construction supervision [5]. It was established as a system to maintain the quality of buildings and protect people's safe lives [5].
75 years later, on April 1, 2025, the registries of First-Class, Second-Class, and Wooden architects, as well as architectural offices, became viewable on the internet [4]. Laid side by side, the name on drawings, the report to the client, and the public registry can all be read as rules that make visible who is responsible. This is our own reading of several sources, not a purpose stated by the people who designed the system.
7. How Can You Try an Architect's Work? Draw a Plan of Your Room and Ask for Feedback
To understand this better, try drawing a simple plan of your own room in a notebook. Draw the walls, door, and window positions, and write down the lengths.
Show it to a family member or friend and ask, "Can you build the same room looking at this drawing?" If they ask questions like "I don't know the window size" or "Which way does the door open?", you have found what is missing from your drawing. An architect's design documents are drawn so that builders can work without confusion, and the name and responsibility remain on them.