What is 4d bim

4D modeling combines a 3D model of an object and its construction schedule, thus indicating the existence of certain elements in a certain period of time. This creates a visually supported calendar schedule of work, which can be made as detailed as possible or, conversely, enlarged.

The entire process of building construction is shown as an animated video with the ability to pause and write comments, identify space-time collisions, and optimize the work of equipment and builders.

The 4D model includes data not only on the construction calendar plan, related to various building elements, but also objects that take part in construction and significantly affect this process. The location of the crane and its area of operation, the number and size of vehicles that can pass through the construction site in a day, the location and size of the construction camp, garbage collection, and much more-all this can and should be taken into account when planning construction. A clear and detailed visualization of the calendar plan allows not only to eliminate various errors, but also to optimize the process immediately before the start of construction.

Advantages of 4D over traditional technologies

Just like the transition from paper-based design to CAD, the transition from CAD to BIM opens up many additional and previously unseen opportunities. Using BIM not only reduces the number and criticality of errors, but also increases the productivity of designers and significantly improves the quality of the final product. 4D technologies allow you to synchronize the model with calendar schedules and see exactly at what point in time what structures should be erected, check building elements for intersections, analyze costs in a basic way, literally "walk" around the object, etc.

Types of collisions

First of all, let's define what collisions can occur during the design and construction process. By the nature of the intersection:

• Physical-intersections in the model of static elements.


• Intellectual (or logical) collisions – collisions in which elements are incorrectly arranged in terms of the process of interacting with them. They cannot be detected automatically (for example, a pipe that covers a door is not physical and will not be visually displayed anywhere as an intersection of elements, but it is a gross error and must be corrected by the BIM coordinator).


• Space-time – intersections between elements, taking into account the time factor (elements or one of the elements is moving). For example, 4D allows you to take into account even such subtle points as how workers conduct work on a specific section of a construction site. No equipment or building structures can be located there at this time. If the location of workers and equipment in a particular time period is not taken into account and they intersect, interfering with the construction process, this is a space - time collision.

Physical and intellectual collisions often relate to the object itself and the structures and equipment that make up it. Space-time refers to temporary structures, construction equipment, and the movement of workers around a construction site. Such intersections are difficult to take into account in traditional design, and their presence in the project depends entirely on the professionalism of the specialist.

By location of detection:

• Internal – intersections between elements inside the building.


• External – intersections between building elements and equipment, temporary structures, etc. while working on a construction site.

A special mention should be made to the competent study of the congestion of the entrance to the site. It is not uncommon, especially in high-density construction environments, when one large piece of equipment can block the entrance to the site for trucks with materials, etc., which leads to delays and downtime in the construction process. 4D modeling also allows you to regulate and optimize this process.

4D modeling makes it possible to almost completely eliminate all types of collisions, including those that are difficult for a specialist to perceive spatio-temporal – by building dynamic visualization and automatically detecting intersections.

Why us

As you can already read on the page dedicated to BIM technologies, designing in 4d bim is only 5% of the budget allocated for construction, while mistakes made at this stage lead to very expensive consequences.

For clarity, we will again give a graph. However, it should be noted that the detection of space-time collisions in traditional design occurs mainly at the construction stage, when the cost of error is highest.