Question 1

What are BIM dimensions?

Accepted Answer

BIM dimensions describe different layers of information added to a BIM model. The most common dimensions are 3D, 4D, 5D, 6D and 7D.
3D focuses on geometry. 4D adds time and scheduling. 5D adds cost information. 6D is often related to sustainability or performance. 7D is usually connected with facility management and operation.
These dimensions are useful as concepts, but they should not be treated as strict universal standards. Project requirements should always define exactly what information is needed.
NBS explains BIM dimensions from 3D to 6D as added layers of information that support better project decisions. Autodesk also describes BIM dimensions as extensions beyond 3D model information across time, cost, sustainability and lifecycle uses.

Question 2

What is 3D BIM?

Accepted Answer

3D BIM is the geometric model of a building, system, product or component. It shows size, shape, location and spatial relationships.
For contractors, 3D BIM helps with coordination and understanding how different systems fit together. For manufacturers, 3D BIM helps represent products or custom components inside the project model.
However, 3D BIM should not be only visual. A useful 3D BIM model should also include the right parameters, categories and project information.

Question 3

What is 4D BIM?

Accepted Answer

4D BIM connects the 3D model with time or schedule information.
This allows project teams to understand construction sequencing, installation phases, site logistics and project progress. A contractor can use 4D BIM to review when specific systems or components should be installed.
For subcontractors, 4D BIM can be useful when their work depends on other trades, site access or phased construction areas.

Question 4

What is 5D BIM?

Accepted Answer

5D BIM connects the model with cost information.
This may include quantities, rates, budgets, cost estimates or cost planning data. It can help project teams understand how design or coordination changes affect cost.
For contractors, 5D BIM can support quantity take-off and cost control. For manufacturers, it can help connect product options, quantities and specifications with commercial information.

Question 5

What is 6D BIM?

Accepted Answer

6D BIM is usually connected with sustainability, performance, energy analysis or lifecycle considerations.
This may include energy performance, carbon data, environmental impact, maintenance planning or lifecycle cost information, depending on how the project defines 6D.
For manufacturers, 6D BIM can become relevant when product data needs to include performance, sustainability or lifecycle information.

Question 6

What is 7D BIM?

Accepted Answer

7D BIM is usually related to facility management and operation after construction is complete.
It may include asset data, maintenance information, warranties, serial numbers, replacement information, manuals and operational data.
For manufacturers, 7D BIM is important when product information must support the building owner after handover. For contractors, it can be relevant when the project requires structured as-built and asset information.
COBie is often connected with this kind of asset and facility-management data because it organizes information needed to manage and maintain facility assets.

Question 7

Are BIM dimensions official standards?

Accepted Answer

BIM dimensions are useful industry concepts, but they are not always defined in the same way by every country, client or project.
3D, 4D and 5D are widely understood. 6D and 7D are also commonly used, but their exact meaning can vary. Higher dimensions such as 8D, 9D or 10D are even less consistent.
For this reason, it is better to define the required BIM uses clearly in the BIM Execution Plan instead of relying only on dimension labels.

BIM Dimensions