BIM

What Is Classification And Why Is It Important?

Digitalisation of the construction industry introduces many opportunities in all parts of the building lifecycle. In the design phase, it helps in the analysis of a larger number of possible solutions. In the construction phase it helps to speed the construction process up and make it safer, and the main benefits in the operation and maintenance phase are facility monitoring, and process optimisation that leads to lower energy consumption. As a consequence of these processes, a very large amount of data is created. In order to use the data effectively, it is necessary to develop an efficient data storage mechanism to ensure their adequate usage.

Historically, the analog data storage presented a limiting factor to better data usage, but the advancement of BIM enabled a more intuitive way of storage by putting it in the context of a 3D building model. To sum up, technology enables creation of huge amounts of data as well as a digital way of storing that data, but one of the main problems still remains, and that is development of a system that would enable us to reach the right data at the right time, when it is needed to make an informed decision. As an illustration, a study conducted by Autodesk & FMI estimates that bad data could have cost the construction industry as much as $1.84 trillion in 2020. It is therefore clear that the data in the industry should be organised in a way that would make collaboration between all the stakeholders. A part of the solution could be implementation of one of the classification systems.

The simplest way to describe classification is as a system to organize and access the required information. The most famous classification system is the biological classification, which categorises living beings. Classification in the construction industry is a process assigns a specific code to all the building entities, thus enabling their distinction. Classification has been present for a long time in the construction industry, with many classification systems being developed through time, depending on the area of the industry whose requirements it was supposed to meet. Currently, 4 classification systems are predominantly used throughout the world. They are analysed in a paper made by K. Afsari and C. M. Eastman, and their characteristics are shown in the table in Figure 1.

Each classification system is unique in its certain way, so it would be the best to decide which one to use in the beginning of the project. That is usually defined in the BIM Execution Plan (BEP). If the decision has not been made beforehand, the Uniclass system is mostly applied in Europe, and is compliant with ISO 19650, the standard that defines information management in the

System Name OmniClass MasterFormat UniFormat Uniclass

Origin North America North America North America North America

Purpose and properties Organization, sorting and retrieval of product information for all objects in the built environment in the project life cycle. A master list for organizing construction work results, requirements, products and activities. Mostly used in bidding and specifications. A master list for organizing construction work results, requirements, products and activities. Mostly used in bidding and specifications. For all aspects of the design and construction process. For organizing library materials and structuring product literature and project information

Framework ISO 12006-2, ISO 12006-3, MasterFormat, UniFormat, EPIC

Grouping principle faceted ISO 12006-2, ISO 12006-3, MasterFormat, UniFormat, EPIC

hierarchical ISO 12006-2 , Professional judgment

hierarchical ISO 12006-2 , SfB, CAWS, EPIC, CESMM

faceted

Organization and taxonomies 15 inter-related tables categorized by number and name. A combination of Table 21, Table 22 & Table 23 allows for classifying a product precisely. One table with a series of six numbers and name: Level one with 50 divisions (2004 version) each is made up of level two, level three, and sometimes level four numbers and titles for more detailed areas of work results. One table with alphanumeric designations and titles in five levels: level one is in nine categories separated by their special function. Level 2 separates them into constituent parts, level 3, 4 and 5 further The division among facets is based on the alphabet in 11 tables and within each facet by decimal scale up to 6 digits. Table G, J, K and L can be used for classifying product models.

Figure 1

Figure 2: Comparison of Uniclass i OmniClass systems [4] construction industry and would therefore be my recommendation. Some other strengths of Uniclass system are regular updates and great flexibility.

It is also necessary to explain the coding system of the elements classified in Uniclass system. The first code element is a combination of two letters that specify which of the Uniclass tables was used in the coding. The other rest of the code consists of two numbers that describe the classified element in more detail, as well as describing the level of detail in the classification, as shown in Figure 4.

Figure 3: Uniclass system hierarchy [5]

Figure 4: Uniclass system hierarchy [5]

Figure 5: BIM Interoperability Tools kartica na alatnoj traci Revita

To understand the mentioned concepts better, an example of classification from highest (Complex) to the lowest d(Product) level will be carried out.

1. The highest classification level is the classification of the whole complex, and therefore the subject is classified as Co_20_15_58 – Office complexes 2. The next step is to classify all the entities in the complex, i.e., parks, bridges, roads etc.

Our analyzed office building will therefore be classified as En_20_15_10 – Multiple occupation office buildings 3. Afterwards, it is necessary to classify the spaces according to their type (classroom, office, conference hall etc.), as well as the type of activity that occurs in a particular space. In example, our analyzed space can be classified as Ac_20_15_50 – Meetings (activity type) and

SL_20_15_15 - Confidential meetings rooms (space type) 4. Finally, it is necessary to classify the building elements of the building, as shown on an example of a curtain wall of our analyzed building. According to function, the curtain wall is classified as a wall element with the code

EF_25_10 – Walls. According to system type, it is classified using the Systems table as a unitized curtain wall with the code Ss_25_10_20_85 –

Unitized curtain wall system. In the end, each part of the panel can be classified using the Pr table, i. e. a part of the frame will be classified as Pr_20_76_51_02 – Aluminum curtain wall frame sections.

IMPLEMENTATION OF A CLASSIFICATION SYSTEM IN A BIM MODEL

After deciding on a certain classification system, it is necessary to implement in the BIM database. Since the primary BIM tool in the Autodesk ecosystem it the BIM Authoring Tool named Revit, it was chosen as the tool to use. The whole process is made easier with the use of a plugin developed by Autodesk, that enables quick classification of building elements. Autodesk Classification Manager is one of the tools in the BIM Interoperability Tools set, developed as a response to a growing need for collaboration between all the stakeholders in a construction project. It enables simple data ogranization, and contains all the mentioned classification systems, as well as a possibility to implement them simultaneously in a BIM model, while maintaining the possibility of development of a custom classification system, depeding on the internal standards of particular user groups.

The tools itself is very simple to use. After installation, a new tab named BIM Interoperability Tools appears on the ribbon. That tab contains a tool named Classification manager, that contains two icons, Setup and Assign (see Figure 5).

The click on the Setup icon opens the Classification Manager User Interface, which enables the user to choose between all the available classification systems.

Figure 6: Available Classification Systems

Figure 7: Assigning classification to chosen elements

After choosing the desired classification system, the elements should be classified by clicking the Assign button. That opens up a new Classification Manager Window which allows the user to choose the category to assign the particular element to.

After clicking the Assign button, new Type parameters showing the classification are created in the chosen element (see Figure 8).

It is visible that the process of assigning a certain classification system is made easy in Revit with the utilization of the Classification Manager in Revit. Therefore, the more difficult part of the job is figuring out the specific classification codes for each of the elements. That is where a guide through Uniclass system could prove useful. Application of this kind of classification enables better interoperability between various stakeholders, but it also creates a possibility of automating certain part of workflows in the future. In example, the Equipment Data tool in the BIM Interoperability Tools set can be used to create a predefined parameter set that would be embedded in elements depending on the classification. That help maintaining a unified structure of parameters that get exported from Revit to other software tools, i. e. Autodesk Tandem, the tools that is used to create a digital twin model to be used in the O&M stage of the designed building.

Marin Ljuban was born in 1994. After finishing primary and secondary school in his hometown, he went to study in the capital, Zagreb, in 2013. He attained a Bachelor of Science in Mechanical Engineering in 2019., and a Master of Science of Mechanical Engineering in 2021. After spending some time working as a HVAC engineer, he got employed as a BIM Application Engineer at an Autodesk Gold Partner in Croatia, Prior Inženjering, helping companies implement BIM solutions in their workflows. Besides Croatian, he speaks English and German.

REFERENCES

1. “Harnessing The Data Advantage in Construction.”

Accessed: Nov. 16, 2021. [Online]. Available: https://a. storyblok.com/f/64835/x/137c281eda/harnessing_the_ data_advantage_in_construction.pdf 2. “Hrvatska komora arhitekata.” , https://arhitekti-hka. hr/hr/bim/klasifikacija/ (accessed Nov. 16, 2021). 3. K. Afsari and C. M. Eastman, “A Comparison of

Construction Classification Systems Used for

Classifying Building Product Models Cloud-BIM and Internet of Things (IoT) View project,” 2016, doi: 10.13140/RG.2.2.20388.27529. 4. “The Definitive 2018 Guide to BIM Classification

Systems.” Accessed: Nov. 16, 2021. [Online]. Available: https://www.kreo.net/ 5. “TfNSW Application of Uniclass 2015.” [Online].

Available: https://confluence.transport.nsw.gov.au/ display/DMS/Digital+Engineering