By reclassifying 4D into two chains of thought – passive and active - the sector is turning 4D BIM on its head.

Here’s an extremely simple formula to convey the concept of 4D BIM: 3D models + time information = 4D. Of course, it’s a bit more complicated in actual usage, though most construction industry professionals have at least a cursory knowledge of how it works. In the 4D BIM process, 3D models are combined with time and schedule-related information such as projects, site surveys, and logistics models. The result is the creation of a virtual construction sequence.


The integration of time to the model improves the model’s functionality for project teams, effectively closing the gap between design and construction. 4D BIM brings with it a number of other significant advantages, including:

· Developing a deeper understanding of the project plan

· Providing a clearer picture of the project deliverables, timescales and methodology, which leads to a safer design and construction process.

· Demonstrating a virtual representative of the construction process, leading to the identification of risks and issues before they become expensive mistakes.

· Tracking project changes and their impact on the timeline.

· Bringing the project to life by simulating the build in 3D, simplifying the consultation process with stakeholders.

There are scores of additional benefits, many of which are already known to industry professionals. In fact, the concept of 4D BIM is hardly a new idea within digital construction – its potential to achieve greater precision on construction timelines and minimize financial risk is well known by business leaders and planning teams alike.

Despite these eye-opening benefits, there’s a problem with 4D BIM: the manner in which 4D is currently being used remains fundamentally flawed. The issue is a strong reliance on outdated “2D” processes and a lack of understanding of 3D models as effective planning tools. The result is that 4D BIM has a perception problem; it’s no longer being seen as a value-added construction tool.

The good news is that this scenario is about to change for the better. The catalyst? Teams will soon be looking to actively use 4D models to plan and forecast, updating as they evolve, rather than passively using the designs solely as a visualization tool. It’s an approach that, at its core, is objectively different to common working practices around 4D BIM. Yet despite going against the grain, it’s proving to be a game-changer in terms of project deliverables – reducing risk and project overrun while increasing bottom lines.

2D Tool in a 4D World

To understand why passive 4D BIM needs to evolve, we must first analyze the construction industry’s current approach to project forecasting and its use of 4D BIM. Currently, construction teams are still opting for inaccurate planning methods. 2D Gantt chart-style formats initially form the basis of 3D models; 4D BIM is then possible by integrating project scheduling information, turning 3D models into detailed planning tools.

However, once projects begin to progress, 4D BIM is quickly abandoned in favor of the tried-and-tested but ultimately flawed 2D format. Should a client then request an updated 4D model further down the line, planning teams must then scramble to obtain a revised version. It’s not difficult to see why, previously, this has been a costly and timely exercise – as well as an illogical one.

It also means that 4D BIM is reduced to a mere visualization tool. Not only does this create unnecessary expense for stakeholders, but for planning teams, it overlooks the ability of 4D to understand construction timelines and calculate risk. In the end, the result is nothing more than 4D just for the sake of it. This is a scenario I refer to as “Hollywood 4D” – a great show with no substance.

The process of creating 2D Gantt charts can, in itself, take months, depending on the complexity of the project. Major infrastructure projects such as airports or nuclear power stations, for example, require the creation of hundreds of data fields, each containing myriad project specifics.

This 2D approach also requires time-intensive manual input from multiple teams, whether it’s the architect, engineer, or contractor. This antiquated approach then fails to record the level of detail and nuance needed at each stage of construction.

Staying active

This is where what we at Elecosoft call Active 4D® comes into its own. By reclassifying 4D into two chains of thought – passive and active - the sector is turning 4D BIM on its head. Passive is the use of a 3D model simply to visualize plans once data has been manually entered; conversely, active is fundamentally different and adopts a more dynamic stance.

This works by using the 3D model during the entirety of the planning process to ensure that the project is correct, first time around. It also allows for a deeper level of information to be attached to design plans, using data linked to digital objects for greater oversight and future gazing. In the end, it means greater precision around risk and cost calculations as well as a more informed client, who now has a better understanding of the necessary timeframes for completion.

The Root of the Issue

Given that the construction industry’s approach to project planning and scheduling hasn’t seen meaningful change in nearly a decade, it’s no surprise that widespread project overrun is now standard practice. In fact, a study by Cornerstone Projects, an underground utility provider, found that the main cause of project overrun in 2022 was poor original planning and unrealistic scheduling.

But that’s just the beginning. Almost nine in 10 construction professionals experienced project delays in 2022 – a rise of 6% since 2016. If the sector is serious about fixing its productivity problems, then methods such as active 4D should be embraced with open arms.

This approach also presents another opportunity: the chance for construction leaders to become early adopters and spearhead this new, innovative approach. By doing so, businesses may be able to more effectively manage time, money, and risk. Doing so will prevent many of the problems that have stifled construction growth. In fact, at a time of wafer-thin profit margins, 4D BIM, or more specifically, Active 4D, could be the way to move the industry ahead not by tiny steps but by leaps and bounds.