Standards Development

Scope

This proposal for a Technical Specification (TS) describes and compares methods for connecting geometric model objects to technical specifications.

Purpose

When using building information modelling (BIM) in construction projects, a key issue is to decide on
appropriate methods for creating, storing and communicating data. Depending on the need of the
receiving party of an information delivery, the balance between alphanumeric and geometric data
needs to be addressed.
Traditionally, geometric models—sometimes called CAD models—are used for producing drawings
and 3D models for the user e.g., to orient, to find objects, and to extract parts lists and volume
calculations. The geometric model is typically complemented by written technical specifications.
These are usually produced by different actors, and the link between them is usually non-existent.
The result is that it is hard for the user to find the description on how to construct a specific object
found in the geometric model.
These specifications—which serve multiple roles including defining project quality, demonstrating
regulatory compliance, and serving as legal documents—must be given a much higher weight since
they are the basis of every works contract for a construction project. Integrating these with geometric
models creates a single source of truth that supports various project phases from design to construction and maintenance. This integration aims to eliminate discrepancies between different document types (e.g., specifications and 3D models), which can lead to increased costs and disputes. A unified approach with distributed data storage is expected to streamline project workflows, making it easier for project managers and contractors to access and compare requirements from all sources.

The evolving construction industry requires adaptable systems that can handle both structured and
unstructured data. By connecting specifications with 3D models, a flexible and comprehensive project
information management will align with modern construction practices. The integration of specifications
and 3D models will justify the benefits of improved documentation quality, enhanced project
management, and reduce conflicts and costs, ultimately aiming for a more efficient and cohesive
construction process.

Technical and non-geometrical specification of an object—material, allowed deviations, production
method and so on—may be stored as discrete object properties. This data can be read directly in the
geometric model or exported to a structured document.
However, storing too much alphanumeric data in geometric models can be time consuming and limit
the number of people contributing. Quality assurance will also be more difficult.
The proposed solution is to store geometric object and their construction specification in separate digital environments, then linking the different kinds of data using a method described in this Technical
Specification. It is recognized that depending on the IT maturity and thus choice of tools, different
approaches can be used to achieve the desired outcome.