buildingSMART Data Dictionary (bSDD)

buildingSMART’s service for sharing definitions for describing the built environment to help everyone use agreed and consistent terms


What is bSDD?

About Content Purpose

bSDD is a collection of interconnected data dictionaries with definitions of terms to describe the built environment. The service is provided by buildingSMART for free, to enable easy access from all software solutions.

The content is published by independent organisations, spanning international classifications, national standards and company-specific agreements.

Search the bSDD content

e.g. wall, or volume

or browse popular data dictionaries

by buildingSMART International

by ETIM International

by NBS

by Molio

or access the content through software

Revit plugin
by VolkerVessels, Heijmans

by IfcOpenShell Contributors

by ACCA Software

by Plannerly

Get familiar with bSDD

Basics Demos Other

Frequently Asked Questions

There are many bSDD user groups, let's group them based on their use case:

  • referencing (example: designers, asset managers) - those who apply definitions from bSDD by referencing in BIM data (IFC and native models), enhancing information depth and consistency.
  • quality control (example: BIM coordinators/managers) - those who want to ensure BIM data meets required standards, leveraging bSDD for compliance checking.
    data analysis (example: contractors, clients) - those who receive and read BIM data benefit from transparent definitions, metadata and mapping to other systems, helping with decision-making.
  • publishing (example: standardization bodies, manufacturers) - for those who want to distribute their standard, classification system, and sets of properties, bSDD offers a common framework for hosting and mapping data dictionaries with a single integration to many software solutions.
  • developing software - vendors use bSDD for seamless integration with many data standards collected in one database with a robust API.
  • other - bSDD is a thorough dataset of interconnected classification systems that is being used by researchers and AI algorithms to gain better insights into data patterns.

No, bSDD is a service from buildingSMART International supporting the openBIM® workflow. The definitions from bSDD can be referenced in IFC models and IDS specifications. bSDD is implementing concepts covered in ISO standards: 12006-3, 23386 and 23387.

First of all, it’s not the complete IFC schema, just the data dictionary of IFC, and only the definitions that describe tangible objects (example: Pipe), not abstract (example: Annotation). The actual technical documentation of IFC is available at our websites.

IFC, apart from being a data schema, contains a collection of semantic definitions of objects and properties to describe them. This is why we have decided to distribute them through bSDD so that users can read, pull and reference those definitions. Additionally, it is important map how other standards relate to IFC.

At the moment, only IFC4.3 is in bSDD, but we are working on publishing previous and future versions and translations to many languages.

bSDD is FREE for both accessing and publishing public content. Isn’t that great? The service was built thanks to buildingSMART members and supporters.

Apart from the key functionalities, which are free, there are also additional paid features, such as the ability to share dictionaries with limited people (private content). If you would like to know more or contribute to the bSDD development, contact us!

bSDD holds all sorts of definitions, including classification systems, ontologies, national or domain-specific standards and even companywide or project-specific agreements. However, it is not supposed to contain project- or product-specific terms, as those are not neutral, universal and reusable.

The content is organized into classes, properties, and relations between them. Each data dictionary belongs to the organisation that published it. The content is not free-form. It has to follow bSDD data model, which is based on international standards ISO23386 and ISO12006-3. Read more about the bSDD data model.

Almost anyone! But we do have some requirements. First of all, content is published by organisations, not individuals, and they take responsibility of it. All publishers need to adhere to strict quality guidelines for structuring data. The content also has to be related to the built environment and relevant to actual user needs, meaning it should be universal and reusable. Project- or product-specific terms are not allowed.

To start, fill out the form Request new organisation.

bSDD is a service provided by buildingSMART International, and we are responsible for ensuring the platform's quality, security, and functionality. The platform is a place to distribute already-developed data dictionaries, not to create them.

The content of bSDD is governed by independent organisations that publish it. They follow their procedures to ensure the quality of the definitions. bSDD allows every publisher to provide information about their quality procedures. We recommend following the ISO23386 standard.

We provided users with options to filter the definitions according to their needs. For example, it is possible to view only content that is coming from trusted organisations and is not a draft or outdated.

We are also working on setting up a thorough verification procedure that will give credibility to dictionaries that have gone through it.

It is very important that once we put references to definitions in contracts and in our data, those will remain unchanged. bSDD has a clear indication of content status. Once something is published, it is first in Preview status. At this stage, it can be modified or even deleted. As soon as the content is mature, the owner can change the status to Active. From that moment, the content will remain in bSDD in an unchanged form and with an immutable identifier (URI). When changes are needed, the owner can publish a new version of the content, and change the status of previous content to Inactive, but the deactivated content will remain in bSDD unchanged.

Read more about the lifecycle of the bSDD dictionary version:

There is an option to always reference the latest definitions of a given dictionary. Read more about it here:

The list of software integrating bSDD is growing and can be found here: Software Implementations: bSDD. Some tools allow viewing the content of bSDD, some also reference bSDD inside IFC models and IDS specifications, and some tools allow creating and managing data dictionaries. Use filters to find the tool you are looking for.

Is your software not on the list? Let your software vendor know! We provide detailed documentation for software developers on how to integrate with bSDD.

Do you know more tools supporting bSDD? Please add it to the list or let us know.

There is also the possibility to use bSDD 'manually'. You can copy-paste the codes of definitions to your IDS requirements and BIM models, as well as reference the definitions in the form of a URI identifier. Read more about referencing bSDD in IDS and IFC:

Indeed, bSDD has undergone transformation lately to better support the intended use cases. The current bSDD is fully functional and stable, and we are constantly working on improving it and implementing new features.

The major change occurred in 2020 when we moved away from one centrally authored data dictionary curated by buildingSMART experts in favour of a distribution platform for independent dictionaries that can be mapped together by relations. This not only lowered the costs of the service, allowing it to be provided free of charge for most users but also lowered the entry barrier and time for new content to be added. The current approach better reflects the reality where many independent systems and data structures exist, and what is useful in one context might be confusing in another.

In 2023, we also renamed parts of our data structure based on industry feedback. What used to be called 'Domains' are now 'Dictionaries', and 'Classifications' are now simply 'Classes'.

Apart from that, we post about all technical updates on our forum:

Do you have questions about bSDD?

Integrate bSDD


The bSDD API is the primary interface to interact with the bSDD database. Read more about bSDD data structure and how to integrate with bSDD in our documentation for software developers. Ask technical questions and get notified about latest technical updates by subscribing to our forum.

bSDD is a Strategic Project supported by:

Explore other buildingSMART Standards and Services