Complex spaces can be realized through programming. Environmental measures to reduce CO2 emissions

technology

BIM──Building Information Modeling

The latest tools to evolve your creativity and production

Among the many technologies that support spatial creation, BIM (Building Information Modeling) is one of the most popular at present. With BIM continuing to evolve day by day, the way work is done is about to change dramatically, from spatial design, layout to on-site construction. At the same time, it will be easier for customers to get a concrete image of the space, and it will be possible to respond quickly and flexibly to various requests. In addition, it is expected to reduce the burden on the environment.

NOMURA began its BIM initiative in 2017. It has steadily built up a track record while continuing to promote the use of BIM within the company. But what exactly is BIM, how will it change spatial creation, and what uses can it be used in the future? We spoke to Taenaka Masataka (Room Chief, BIM Room, Creative Headquarters concept design Development Center), who has been working to promote BIM within NOMURA, and Nitasaka Takuto (General Manager, Product Direction Division 2, Fourth Business Division, Sales Promotion Headquarters), who has been exploring ways to use BIM in the field of spatial creation, about the current state of BIM.

[BIM] and [3D CAD] are similar but not the same

The first case in which NOMURA fully implemented BIM was Tokyo Mizumachi, which opened in 2020 near Tokyo Skytree. The project involved developing a commercial facility across an area that combined Sumida Park and the waterfront of Kitajukken River, and required the consensus of many stakeholders and organizations. And Taenaka says that this initial experience was extremely valuable.
 

"At the time, BIM was just beginning to take hold in the construction and building industries. However, it was still hardly used in our industry. So we tried using BIM for the first time at Tokyo Mizumachi, and found that communication went very smoothly, including in meetings with the client and discussions with government agencies. We could show an image of the finished product in VR, so you could walk around the facility freely and consider it from various angles. You could change the position and size of the windows to check how the view looks. It's easy to change the lighting to see the atmosphere.

The level of understanding among the people involved and the sense of speed in the project both increased dramatically. This led to an acceleration of the use of BIM within the company."

Meanwhile, Nitasaka says that the introduction of BIM has significantly changed not only communication with clients, but also the work flow itself.

"Until now, two-dimensional plans and development drawings would be made first, and then angles and light would be specified based on those to create a three-dimensional perspective. At NOMURA we use Autodesk® Revit® software for BIM, which allows a three-dimensional space to be created on the computer from the start. This makes it easier for clients to understand, and if they say they want to change the position of a window, for example, we can move it and show them on the spot. What's more, the moment you move it, the change is reflected in all the drawings.

In the past, I would take the client's request home, revise the plan and development drawings, redraw the 3D perspective, and bring it back a week later. Not only is it easier to communicate with the client, but it also reduces the number of "returns," so we can reach an agreement more quickly.

The strength of BIM is that a single modification is reflected in all drawings in real time, and even though 3D images can be viewed in the same way, this is what makes it fundamentally different from 3D CAD.

"The information held by the two is completely different. 3D CAD only contains shape information. For example, floors, pillars, doors, etc. are drawn on a blueprint, but 3D CAD only digitizes the shapes, and does not know whether they are floors, pillars, or doors. On the other hand, BIM holds the data as floor, pillar, and door information. So, if you ask how many pillars there are or the area of a wall, you will get an answer instantly. So BIM is not just 3D shape data, but a database that contains all the elements that make up the space, such as the blueprint, the materials and equipment used, etc. From that database, a 3D image is generated and displayed." (Myonaka)

Dramatically improved concept design freedom

So how is BIM actually used in projects?

"There are different ways in which it can be used in the fields of concept design and production, but in the field of concept design, 'visualization' is a big help. When trying to realize a space with a complex shape, it is difficult to fully express it with just two-dimensional drawings.

For example, we were once commissioned to create a display in which 150 pigeons were flying overhead in a large hall. The pigeons were hung one by one from the ceiling, but positioning 150 pigeons in a three-dimensional space was incredibly time-consuming using two-dimensional drawings. Corrections were also difficult. It was more realistic to use a program to create a 3D image and proceed while checking how it would actually look. Furthermore, when it came to creating several concept design, it was impossible to keep up with the time and energy required to do it by hand. With BIM, you could create a different concept design by tweaking parameters such as the density of the pigeons' placement or the curve of their flight." (Myonaka)

Furthermore, the power of "visualization" is also great in terms of production. Nittasaka says that BIM has also contributed greatly to improving the efficiency of construction at one site.

"I was in charge of hanging an LED light object from the ceiling. There were ducts and wiring running above the ceiling, and we had to make sure that the object did not interfere with them when hanging it. Before the advent of BIM, we had to manually find the positions of the object's mounting hardware by overlaying all the drawings for the ducts, wiring, structural beams, and steel frames. On-site, we sometimes had to build detouring supports or use unconventional mounting methods to avoid ducts and wiring that had already been construction.

But with BIM, we can properly arrange the pieces from the beginning so that they don't interfere with each other, so we don't have to worry about that on-site. We can also consider in advance how to open the inspection panel so that light bulb replacement work can go smoothly later."

Using BIM to reduce CO2 emissions

The use of BIM also goes further to reduce the environmental impact.

"We were asked by an overseas brand to create a store, and we incorporated BIM as much as possible.®® With 3D images, you can see at a glance the construction process for each floor, such as walls and floors, ceilings, and fixtures being brought in. It's easier to check than a huge document schedule.

BIM was also used for the design, layout in the store, and the construction was pre-cut based on the data. In the past, materials with fixed standards would be brought in, cut on site, and fitted, but BIM would tell us the exact size of the materials we needed, so we would bring in materials that had been cut at the factory in advance. Even the gypsum board, which is not usually pre-cut, was cut and brought in. Then, the materials brought in are assembled like a puzzle on site. Sometimes, I don't know where the piece fits, and it's faster to cut it than to look for it!  There was also a scene where the craftsman cut it on site (laughs). It's a matter of getting used to the site.

So, since there were floors that were proceeding without using pre-cuts, we were able to obtain comparative data to see how much difference there was between conventional construction and pre-cut construction. First of all, in terms of work efficiency, the amount of gypsum board that craftsmen can work on per unit of time is about 1.8 times that of the conventional method for the pre-cut method. In addition, with the pre-cut method, there is less waste because it is not cut on site. Waste is reduced by about 15% for gypsum board and about 30% for metal substrates.

In addition to reducing waste, the pre-cut method also reduces the amount of materials originally brought in, so the environmental impact of transportation is also reduced. In the end, the pre-cut method and the conventional method were mixed at this site, but we were able to reduce CO2 emissions by about 13% in the total project total. Every company is working hard to achieve carbon neutrality right now, so I think it will be of great benefit to our customers that BIM can contribute to that."

There are also projects where BIM can link concept design and production aspects to improve efficiency.

"I am running a shop for a certain brand that has a nationwide presence. The shape and floor space of the buildings in which the stores are located vary depending on the location, but the brand's worldview must be consistent.

So, for example, all the elements necessary to create a worldview, such as the interiors boards and product display fixtures, are registered in BIM beforehand. Using these, the designers can create multiple plans, and the production team can work efficiently." (Taenaka)

BIM continues to be used after the space is created

BIM continues to evolve every day, but Taenaka says he wants to develop it not only to improve production efficiency, but also to expand creativity.

"Because BIM is a database, adding new data increases the things you can do. For example, with lighting fixtures, you can create a more realistic 3D image by adding not only the light source specifications of the fixture but also the light distribution data. Lighting is reflected on the walls and glass of a room. You can check these reflections in BIM, so you can incorporate them as concept design elements.
In addition, at displays where many companies are participating, the layout of the entire venue, not just the booth you are in charge of, is digitized. This allows you to position the logo of your booth so that it is easy to see from anywhere in the venue.

Or, when renovating or renewing an old building, the architectural drawings may no longer be available. Even if there are, they often differ from the current situation. In such cases, you can use a laser scan to obtain 3D data of the building and input it into the BIM. Current laser scans have an error rate of about 4 mm at 10 m, so they are quite usable. They can also pick up the unevenness of small constructions, making them more accurate and easier to use than measuring by hand with a tape measure. They are also useful for preserving cultural assets.

From a sales perspective, by being creative with the data we input rather than just providing estimates, we believe that salespeople and planners will be able to propose plans to customers that also include simulations of sales and profitability when a facility is built."

BIM is useful not only for creating spaces. For example, by constructing a "digital twin," a 3D twin of a real space, it is expected to be used to solve various problems. It is said that it is possible to simulate various patterns of people flow in a facility that attracts visitors on the digital twin, and then adopt the best option in the real facility.

Aiming for a future that creates even more added value than ever before, Myonak and Nitasaka say they will continue to promote the further spread of BIM use.
 

(Interviewed in December 2023. Titles in the article are those at the time of the interview.)