UniClass 2015 Classification of IFC objects
IFC and classification systems: how to add a classification to the entities of an IFC model according to the UniClass 2015 system
Do you need to classify the entities of an IFC project? Or do you need to read the classifications associated with the entities contained in an IFC file? In this article, I will explain what the UniClass 2015 classification system is, what it is used for, and how to use it to classify and add information to the entities of an IFC model.
In this article, I will show you how to associate or modify a UniClass 2015 classification entry directly on a 3D model using an online IFC editor, in just a few simple steps.
UniClass classification of IFC objects
Contents
What is UniClass 2015 (Uniclass 2015 classification)?
Origin of the UniClass system
UniClass (Unified Classification for the Construction Industry) is a classification system first introduced in 1997 in the United Kingdom by the Construction Project Commitee. It was developed as an integration of existing standards such as EPIC (Electronic Product Information Cooperation) and CAWS (Common Arrangement of Work Sections for Building Works).
Within the construction industry, UniClass can be defined as a “faceted” classification system, partly based on an enumerative approach, which applies a classification method structured around 15 tables organized in a hierarchical framework.
How the UniClass classification works
More specifically, the tables included in the UniClass classification are the following:
- Complexes: describes a project as a whole. It can refer, for example, to residential developments, sports facilities, school buildings, airports, etc.;
- Entities: represents one of the parts (or zones) that make up a facility. It may include buildings, bridges, or tunnels within a larger infrastructure system;
- Activities: represents the activities carried out within a complex or an entity. For example, within a school building there may be physical, administrative, recreational, and educational activities. The table also includes investigation, operation, maintenance, and services;
- Spaces: may host one or more activities within a built asset or within non-point infrastructures such as road networks, railway systems, etc.;
- Elements: these are the main components of a structure. For instance, in a residential building, elements correspond to slabs, columns, walls, etc.;
- Systems: represent a set of components assembled to form an element or to perform a specific function. For example, a roof system may consist of tiles, insulation layers, vapor barriers, beams, etc.
Graphical scheme explaining the organization of the tables in the UniClass 2015 classification system
Structure of the UniClass 2015 tables
In addition to the tables described above, the UniClass 2015 system is structured around classification tables. Each table addresses a specific information domain and can be used individually or combined with other tables to express more complex concepts.
Below are the titles and the main contents of the tables.
The 15 original UniClass tables
The tables shown below were in force from 1997 until 2015.
| CODE | TITLE | CONTENT |
| A | Form of information | Documents are classified both according to the type of content (catalogues, price lists, etc.) and the medium used (journals, videos, etc.). |
| B | Subject Disciplines | Disciplines related to the construction sector. |
| C | Management | Concepts related to decision-making processes. |
| D | Facilities | Civil engineering works. |
| E | Construction Entities | Concepts related to buildings, pavements, bridges, and viaducts. |
| F | Spaces | Concepts related to building spaces, regardless of whether they are internal or external. |
| G | Elements for buildings | Concepts related to in-place elements belonging to the building construction sector. |
| H | Element for civil engineering works | Concepts related to in-place elements belonging to the civil engineering sector. |
| J | Work Section for buildings | A complementary classification to building works focused on “work sections”. |
| K | Work section for civil engineering works | A complementary classification to civil engineering works focused on “work sections”. |
| L | Construction products | Construction products. |
| M | Construction aids | Site equipment and construction aids. |
| N | Properties and characteristics | Properties of the entities subject to classification. |
| P | Materials | Materials. |
| Q | Universal decimal classification | Complex concepts that can be defined by combining multiple specific class codes. |
Evolution of the UniClass 2015 system
Between 2013 and 2015, the UniClass classification tables were reduced from 15 to 11.
| Table 1 | Co | Complex | The project as a whole (villa, university campus, etc.) |
| Table 2 | En | Entities | Buildings classified according to their function |
| Table 3 | Ac | Activities | Activities carried out within spaces |
| Table 4 | SL | Space/Locations | Spaces (rooms that make up the building) |
| Table 5 | EF | Elements/Function | Elements are the main components of a building (walls, foundations, roofs, etc.) |
| Table 6 | Ss | Systems | A set of components forming an element (e.g., boards and studs in a drywall partition, carpentry components forming a door, etc.) |
| Table 7 | Pr | Products | |
| Table 8 | TE | Tools and Equipment | |
| Table 9 | Zz | CAD | Concepts related to information technology applied to construction |
| Table 10 | FI | Form of Information | |
| Table 11 | PM | Project Management |
An element is identified by:
- 1 pair of alphabetical letters referring to the Table;
- 4 pairs of numbers identifying groups, subgroups, sections, and objects.
In the next paragraph, I will show you how to classify any entity (for example a roof, a wall, etc.) in an IFC model.
You can try classifying the elements of any 3D model (IFC, DWG, SKP, etc.) yourself by using a free IFC editor online.
Editing classifications with usBIM.editor
How to classify IFC objects with UniClass 2015
The IFC standard also uses classification systems to categorize project entities and enhance the information system associated with them.
IFC classification with an online IFC editor
How can I practically add new classifications in the IFC environment?
Below is a practical example of how to classify a project entity with usBIM.editor according to the UniClass 2015 system:
- access usBIM;
- open the IFC file;
- select usBIM.editor (top left);
- click on
Edit classifications; - select a model entity;
- add a new classification;
- fill in the editable fields;
- associate a standard classification system;
- choose the classification type;
- select the subcategories to associate with the selected entity;
- view the changes in the properties toolbox.
How to verify the UniClass classification in an IFC file
If you want to check whether the classification has been associated with an element, you can use a simple free online BIM viewer that allows you to visualize any element and check all its properties.
Verification with a BIM viewer
With usBIM you can proceed as follows:
- open the IFC file with usBIM;
- select the entity of interest (for example a door, wall, slab, etc.);
- read the classification information in the properties section located on the right side of the window. Here you will find two sections related to classification:
IfcClassificationReferenceindicates the code corresponding to the type of information added;IfcClassificationindicates the classification system used (in this case UniClass 2015).
Remember that with usBIM.editor you can classify all the elements of your model according to the main classification systems such as:
- MasterFormat;
- NatSpec;
- NBS Create;
- OmniClass;
- SCFclass;
- UniClass (version 2);
- UniClass 2015;
- UniFormat.
Video on IFC file classification
In this video, I show you how, using an online IFC editor, you can assign the UniClass 2015 classification to the entities contained in an IFC model.
FAQ on UniClass 2015 classification of IFC objects
What is the UniClass 2015 classification system?
UniClass (Unified Classification for the Construction Industry) is a “faceted” classification system introduced in 1997 in the United Kingdom by the Construction Project Commitee. It was developed as an integration of standards such as EPIC and CAWS and is used to classify and add information to the entities of an IFC model within the construction sector.
What were the 15 original UniClass tables in force until 2015?
The 15 original tables included: A (Form of information), B (Subject Disciplines), C (Management), D (Facilities), E (Construction Entities), F (Spaces), G (Elements for buildings), H (Element for civil engineering works), J (Work Section for buildings), K (Work section for civil engineering works), L (Construction products), M (Construction aids), N (Properties and characteristics), P (Materials), and Q (Universal decimal classification).
How did the UniClass 2015 system evolve?
Between 2013 and 2015, the classification tables were reduced from 15 to 11: Co (Complex), En (Entities), Ac (Activities), SL (Space/Locations), EF (Elements/Function), Ss (Systems), Pr (Products), TE (Tools and Equipment), Zz (CAD), FI (Form of Information), and PM (Project Management).
How are UniClass 2015 codes structured?
An element is identified by a pair of alphabetical letters referring to the table, followed by four pairs of numbers identifying groups, subgroups, sections, and objects.
How to classify IFC objects with UniClass 2015 using usBIM.editor?
To classify an entity with usBIM.editor you need to: access usBIM, open the IFC file, select usBIM.editor, click “Edit classifications”, select an entity, add a new classification, fill in the fields, associate the UniClass 2015 standard system, and choose the subcategories to be assigned.
How to verify the UniClass classification in an IFC file?
You can use a free online BIM viewer such as usBIM: by selecting the entity of interest, you can read the information in the properties section. The main references are “IfcClassificationReference” for the code and “IfcClassification” for the classification system adopted.
