The aim of the BIM-SPEED project is to:

• reduce the time of deep renovation projects
• develop affordable tools and integrate them into the BIM-SPEED platform
• standardize procedures for implementing renovation solutions

The general objectives of a model check are to ensure the following:

• Safety - that all relevant information is available and that the geometry of the 3D BIM model corresponds to the inventory
• Guarantee - that further work steps based on the 3D BIM model can be processed correctly and without data loss
• Reliability - that all relevant information can be accessed correctly
• Correctness - of the calculated results (no incorrect calculations)
• Time saving - due to automated checking and predefined workflows

With regard to BIM-SPEED project, the specific aim is to ensure that 3D BIM models can be made accessible on the BIM-SPEED platform such that users have access to 3D BIM models that have already been verified.

One of the main objectives of the BIM-SPEED project is to reduce the time of deep renovation projects by 30%. The implementation of model checks makes a major contribution to this, through automated and standardized model check processes, errors in the model can be detected at an early stage and efficiently corrected. Following picture shows the difference between the conventional way performing the checks and effort reduction by implementing automatic model checks. More details follow below.

Figure1: Comparison between conventional and BIM-SPEED approach to model checking

Rather obvious is the reduction of working time to perform the model checks.

Assuming to setup and define model checks for a 3D BIM model LoD (Level of Detail) 400 to 450 of a common residential building with 4 levels and approx. 300m² living space as reference, the time required cumulated is (based on experience):

• Conventional: 5-7 working days
• BIM-SPEED: 2-3 working days

The picture above highlights the inclusion of several manual process steps in the workflow of checking a 3D BIM model in conventional way, while the BIM-SPEED approach clearly outlines the consolidation of all these steps into a single automated process step. This accounts for impactful reduction in time, along with avoiding errors by providing standardized check templates. Furthermore, the possibility to export issues as BCF files, directs the BIM author directly to each issue within his own CAD or viewer software, which enhances the process of verification by avoiding communication errors.

In the course of the model checks,

• Semantical checks on one hand verify the consistence of the elements. That includes checking of the nature of the elements as it might be, that some of the shown elements in the model are not real solid 3D elements. Additionally the existence of all needed parameters will be verified and finally compliance to all the naming conventions (file/ elements/ levels/ layers/ properties etc.) will be confirmed.
• Numerical Checks on the other hand guarantee the evaluation of numerical information provided within the properties. Given values will be safeguarded as well as the correctness of selectable or calculated values.

Combining both types of model checks in the end will assure compliance to national/ regional specific/ other standards and verify ranges along with naming/semantic/other informational requirements for further BIM uses. One main focus is, to ascertain the handover to geometrical verification procedures, like clash detection and/or deviation analysis. These aids avoiding errors in geometrical accuracies and saving costs and time by identifying clashes of different disciplines already in project execution stages.

• The success of the model checks is based on well-defined project-specific requirements in terms of the aimed BIM use cases to be performed. In addition the resulting modeling specifications need to be described in a clear and coherent way.
• The success of the properties testing, on the other hand, depends exclusively on the detail of modeling specifications, which have to be regarded when generating the 3D BIM model. The quality of the model checks can only be as good as the predefined model specifications are. The overall goal is, to create a model and project independent syntax, based on standardized modeling specifications, which makes it possible to test different 3D BIM models with the same procedure.  

Advantages

Standardizing Model Requirements, country-specific features excluded, as basis for the 3D BIM Model generation, will allow to develop a generalized workflow for verifying 3D BIM models in terms of geometry and provided information within the model elements, which can be applied to different models and different projects.