BIM: What Is It? A Comprehensive Guide to the Digital Technology Transforming the Construction Industry

The term “BIM” has become increasingly common in the construction industry in recent years. You might feel it’s too late to ask now, yet still not really know what it means. In this article, we’ll thoroughly explain what BIM is, from the basics to the transformations it brings to the construction industry, as well as its benefits and challenges for adoption. Let’s explore how digital technology is changing construction sites.

What Is BIM?

BIM stands for Building Information Modeling and refers to the method and concept of centrally managing all information related to a building as a three-dimensional digital model. Simply put, it creates a virtual model of a building on a computer and links and manages all kinds of data—design drawings, construction information, component specifications, schedules, costs, and more—within that model.

While traditional CAD handles drawing data such as plans and elevations, BIM treats objects—like columns, walls, windows, and equipment—as the basic units of data. For example, when you place a wall in BIM software, that wall is assigned attribute information such as height, thickness, material, and finish. By combining multiple objects, a 3D model of the whole building is constructed, from which plans, sections, finish schedules, quantity takeoffs, and other documents can be automatically generated. In this way, a BIM model is not merely a 3D drawing but can be regarded as a “database of the building.”

Why BIM Is Gaining Attention

Why is BIM attracting so much attention now? The reasons lie in the structural challenges facing the construction industry and the wave of digitalization.

Japan’s construction industry has long been said to suffer from stagnant productivity. While labor shortages and the aging of skilled workers are progressing, many tasks—such as drawing creation and site management—have relied on traditional manual work. In other industries, especially manufacturing, the use of 3D CAD and digital data has become commonplace, but the construction sector has remained dominated by paper drawings and 2D CAD, leaving digitalization behind.

BIM is expected to be a means to overcome these issues. The Ministry of Land, Infrastructure, Transport and Tourism began the “i-Construction” initiative in 2016 to promote innovation in construction processes through ICT technologies, with one of its pillars being the promotion of BIM use. Recently, the digitization of building permit applications has created a trend in which the use of BIM is becoming effectively mandatory. For example, phased implementation of permit submissions using BIM will begin in fiscal 2025, and from 2026 onward, plan reviews using BIM data are scheduled to become full-scale. It is expected that most construction projects will use BIM in the future, so it is important for the industry not to fall behind.

Benefits and Effects of BIM

What concrete benefits does BIM bring when implemented? Below are the main effects.

• Reduction of design errors and rework: Because the entire building can be examined three-dimensionally in a BIM model, interference checks (clash detection) can be performed early to discover inconsistencies in drawings or clashes between components. This significantly reduces rework and construction errors during the construction stage.

• Improved productivity and cost management: Automation of drawing creation and automatic aggregation of component quantities improve the efficiency of designers and construction managers. Also, based on accurate quantity information, estimates for material costs and schedules become more precise, yielding benefits in cost management.

• Smooth information sharing among stakeholders: Through a common platform in the form of a BIM model, owners, designers, contractors, and equipment suppliers can always share the latest information. Misreading drawings or gaps in understanding are reduced, improving communication losses. The 3D visual information is also useful for explaining designs to clients and building consensus.

• Advanced construction planning and schedule management: BIM enables 4D simulation (construction simulation with a time axis) to replicate construction sequences and schedules in virtual space. This allows detailed planning of crane and heavy equipment placement, material delivery routes, and worker safety measures, contributing to shorter construction periods and improved safety.

• Use for operation and maintenance (FM): BIM data retains value after handover. The as-built BIM model can be used as a digital ledger for equipment management, or referenced as-built during renovations. By carrying information through the building’s lifecycle, and eventually using BIM data for digital twins, advanced facility management becomes possible.

In this way, BIM provides multifaceted benefits at every stage—design, construction, and maintenance.

Differences Between BIM and Traditional CAD

To deepen your understanding of BIM, let’s also review the differences from traditional CAD. The key point is the granularity and consistency of the information handled.

With conventional 2D CAD, multiple drawings such as plans and elevations are created separately and must be manually reconciled. For example, if a column position is changed, all related drawings must be updated, and missed updates can lead to errors. Moreover, CAD drawings themselves do not include quantities or specifications for components, requiring separate quantity takeoffs and reference to specification documents.

In contrast, as noted earlier, BIM consolidates all information into a single 3D model. Move a wall or column, and all associated drawings update automatically—eliminating missed changes. Each object can carry attribute data such as material, dimensions, manufacturer part numbers, weight, and price as needed. In other words, a single BIM model can serve as design documentation while also functioning as estimates and material lists. Because information is centrally managed, any change is instantly reflected across related data, maintaining the project’s “Single Source of Truth.”

In short, if CAD is a “drawing tool based on lines and surfaces,” BIM is an “architectural data platform based on objects and information.”

Transformations BIM Brings to the Construction Industry

BIM implementation is expected to bring about changes not only in individual project efficiency but also in work styles and business models across the construction industry.

First, there is a productivity revolution. BIM streamlines time-consuming tasks such as drawing coordination and quantity takeoffs, enabling smaller teams to produce high-quality outputs even amidst labor shortages. This is an important measure to address the chronic shortage of skilled craftsmen and technicians. The cost reductions from reduced rework also strengthen competitiveness in bidding.

Next is deeper collaboration. A shared BIM platform enables designers and contractors to cooperate closely from early stages via front-loading, fostering collaboration across the traditional divides between design and construction. This leads to improved quality, reduced risk, higher client satisfaction, and fewer claims.

Furthermore, BIM’s digitalization of construction processes encourages the creation of new services. For example, sharing BIM models in the cloud allows remote monitoring of site progress, or combining BIM with VR technologies provides virtual preview experiences for clients—digital-added-value services. In prefab and modular construction, factories can produce components based on BIM data, reducing on-site work. These trends accelerate DX (digital transformation) across the construction industry.

Current Status and Trends of BIM in Japan

Although Japan lagged behind some overseas markets in BIM adoption, activity has rapidly increased in recent years. Many major general contractors and architectural firms are already running BIM projects, and the use of BIM/CIM is expanding in public works commissioned by the national government.

At the national level, as mentioned, a major goal has been set to make building permit applications BIM-compatible. From fiscal 2025, electronic applications using BIM will be piloted in some areas; by spring 2026, reviews using data created with BIM will commence; and by 2029, nationwide adoption of BIM-based applications and reviews is planned. In other words, within a few years, permitting procedures are expected to shift to a BIM-based premise, making industry-wide responses urgent.

Currently, it is said that slightly less than 50% of companies or projects in Japan are using BIM in some form. Surveys show over 70% adoption among practitioners in countries like the UK, highlighting Japan’s lag. To close this gap, the government and industry organizations are investing in training, guideline development, and support measures for adoption. Especially for small- and medium-sized construction companies and design offices, spreading BIM is a challenge; efforts to lower entry barriers—such as cloud-based inexpensive BIM software and simplified BIM tools—are increasing.

Thus, BIM use in Japan is very much in a transitional phase. Companies that gain experience early will strengthen their competitiveness, while those that delay may risk losing work in the future. Adapting to BIM is becoming essential for survival.

Challenges and Key Points for BIM Adoption

While BIM offers many benefits, there are several challenges to its adoption. Understanding these hurdles and taking countermeasures is key to success.

• Initial investment and costs: Licensing for dedicated BIM software and high-performance PCs can require significant initial expenditure. Beyond software, costs and time are also needed for staff training and creating operational rules. The key is whether these can be seen as investments in future benefits rather than expenses to skimp on.

• Human resource development and learning curve: Mastery of BIM software and 3D design methods takes time. After implementation, some tasks may initially take longer than conventional workflows. However, once BIM personnel are developed internally through early trial and error, substantial efficiency gains follow. Planned training—such as sending younger staff to external seminars—is important.

• Workflow revision: BIM adoption is not merely a tool replacement but involves reforming business processes. Information-sharing procedures between design and construction and decision-making processes with clients may need to be rethought. Establishing common rules (naming conventions, model creation standards, etc.) and building cooperative frameworks with stakeholders are required.

• Data interoperability with other firms: Projects involve multiple companies, so sharing and compatibility of BIM data is an issue. Different software may prevent direct exchange of native data, but using neutral data-exchange standards such as IFC format can resolve this. Increasingly, clients provide a platform so all parties can access a common data environment (CDE).

To address these challenges, it is effective to first trial BIM operations on small projects or for specific tasks to build success stories. With management buy-in and cooperation on-site, a phased and planned rollout can reduce risk and support adoption.

Simple Surveying in the BIM Era: Easy Ways to Start Site Digitalization

To maximize BIM’s benefits, accurately and efficiently digitizing site information is crucial. For example, in renovations and remodeling, it is common to survey existing buildings with laser scanners to obtain point cloud data and convert that into BIM models. In civil engineering, drone aerial surveys and 3D scans are increasingly used to create terrain models that serve as foundational data for CIM (Construction Information Modeling).

Previously, such 3D surveying required expensive equipment and specialist skills, but recently solutions have emerged that make it easy to obtain digital site data. One of these is simple surveying using smartphones.

For example, there is a device called [LRTK Phone](https://www.lrtk.lefixea.com/lrtk-phone) that attaches a small RTK-GNSS receiver to an iPhone or iPad to achieve high-precision positioning. With this setup, a smartphone effectively becomes a surveying instrument with centimeter-level accuracy, allowing a single person to easily measure coordinates and elevations. The collected coordinate data can be plotted and managed on maps in the cloud, and by combining the smartphone’s camera or LiDAR scanner, simple point clouds and site photos can be recorded. Tasks that once required specialized surveying teams and costly equipment can now be performed with pocket-sized tools.

By leveraging these kinds of simple surveying technologies, you can obtain high-accuracy site data at low cost, making BIM preparation and digitalization for small projects much more accessible. For instance, even a small renovation can quickly capture as-built dimensions with tools like LRTK and use that data to create a BIM model, allowing planning to proceed efficiently. Skillful use of the latest surveying gadgets that bridge BIM and the field will be key to future construction DX.

Conclusion: Shaping the Future of Construction with Digital Technology

BIM is not just a trendy IT tool—it is a technology with the power to fundamentally change how construction projects are executed. By centralizing drawings and information, BIM dramatically boosts productivity and enables all stakeholders to make data-driven decisions. For an industry facing population decline and workstyle reforms, BIM adoption is an unavoidable future.

That said, reaping the benefits of digitalization also requires efforts to connect real-world sites with data. If you have not yet taken the first step into BIM, start with something easy to adopt and incorporate digital technology. Even simply collecting site data with a smartphone-based surveying tool can make the difference apparent. That can be the first step toward BIM utilization and, ultimately, contribute to productivity improvements across the construction industry. Embrace digital technology as an ally, and let’s shape the future of construction together.