30 March 2023

1. Specification

Bond Bryan Digital have been assisting several clients in both the public and private sectors to set out their information requirements in a series of Information Management Resources compliant with BS EN ISO 19650-2:2018 for capital delivery projects. One client is the Department for Education (DfE), who Bond Bryan Digital assisted in developing their information requirements for their Construction Framework 2021.

The resources developed collaboratively with the DfE include Exchange Information Requirements and a Project’s Information Standard, which is tailored to each specific project. These two resources are critical to setting out, in detail, both the framework and project specific requirements for delivery teams to deliver against.

Exchange Information Requirements

The DfE’s information requirements cover all the information that is required to be delivered to them at all stages of a project, not just building information models, and follow the breakdown of information contained in Level of Information Need standard BS EN 17412-1:2020. The requirements are structured using IFC (Industry Foundation Classes) with Uniclass as the primary classification system throughout, including:

  • Documentation – For documentation the Uniclass PM Project Management table provides an extremely useful structure to build and develop information requirements around. The inclusion of Uniclass allows users to search and filter consistently, using the Group, Subgroup or Section codes.
Documentation requirements utilise the Uniclass PM Project Management table for filtering
  • Geometrical information and Alphanumerical information - There are 200 Elements/ Functions and over 8,000 Products described in the current version of Uniclass. Defining geometrical and alphanumerical information requirements and then maintaining them around this number of codes is highly impractical for clients. However, IFC offers a base object structure for components, whether assemblies or products, which can be drilled into more detail later using Uniclass as an additional filter. Bond Bryan Digital use the IFC entities and their associated enumerations (Predefined Types) to build information requirements for geometrical and alphanumerical requirements, because it provides sufficient granularity based on a fixed schema, in order to document requirements for clients.
IFC entities are used to set out the Geometrical information (and Alphanumerical information) requirements

Project’s Information Standard

The Project’s Information Standard is a key resource that works alongside the DfE’s Exchange Information Requirements. This includes the following which are critical to IFC delivery:

  • Project specific values for Project, Site and Building;
  • Building storey (floor) nomenclature requirements;
  • Space and zone nomenclature requirements;
  • Object type and occurrence nomenclature requirements;
  • System nomenclature requirements; and
  • Standard picklists.

Additionally, the Project’s Information Standard also sets out information regarding the use of Uniclass and how it relates to both the IFC and COBie schemas.

Showing the relationship between IFC, COBie and Uniclass included in the Project’s Information Standard

The Project’s Information Standard also includes the use of the Uniclass Ro Roles table against Originator codes. This information is helpful because it can be used to produce consistent Project Directory Forms, and to populate the COBie Category field for Contact information.

Uniclass Ro Roles used to against Originator Codes (extract)

Another component of the Project’s Information Standard that supports both IFC and Uniclass is CAD (computer aided design) layers. The DfE’s requirement is aligned to BS EN ISO 13567-2. Whilst not all native tools use layers, they are often used to provide another way of filtering and searching information in IFC models. Using layers built around BS EN ISO 13567-2, which include Uniclass codes, also supports model exchange to help improve the process of interoperability between disciplines.

2. Delivery

All models are required to be delivered using an IFC-SPF (Industry Foundation Classes-STEP Physical File) compliant workflow for DfE projects. To support this, Bond Bryan Digital have developed several components to support delivery teams. These include the following:

  • Development of a detailed written guide, supported by corresponding video content, to explain the process for generating valid IFC-SPF models from Autodesk Revit;
  • Provision of supporting configuration files to support each project to deliver the required output efficiently and effectively;
  • Detail set out within the BIM Execution Plan breaking the process down into a number of information exchanges and associated checking; and
  • Training sessions to go through the process with model authors.

Bond Bryan Digital’s role as Information Managers on projects is to support the delivery of compliant outputs by supporting delivery teams to deliver efficient and effective processes. Working with designers and sub-contractors to check and feedback on the delivery as the project develops, so the process is ongoing throughout the project.

IFC-SPF Models

Each model produced in accordance with the DfE’s Exchange Information Requirements needs to provide compliant geometrical and alphanumerical information. The structure of these models is essentially identical across disciplines with the following differences:

  • Only the Architectural model is expected to contain Space and Zone information.
  • Only the Building Services models are required to provide System information.

The advantage of this approach is the structure of building information models, irrespective of discipline or the authoring tools that were used to create these models, will be consistent. For example, the ‘Name’ (which is an Attribute in IFC) required for the Project will be provided in the same location in each file. The ‘Name’ delivered using building information models will also be consistent as the required value is set out in the Project’s Information Standard at the outset of the project. This means delivery teams have full clarity about the information to be provided and Information Managers can check and verify the data consistently.

IFC Schema and relationship to Uniclass for DfE Construction Framework 2021 projects

As part of this standard approach, Uniclass plays a part in providing a consistent way of classifying each Building and the Spaces within them. It also provides consistency in classifying products and elements. In IFC, Uniclass is provided as a ‘Classification Reference’ which includes the Code and Title, but this also is related to information about the Classification system itself. The Classification system information includes the Source (i.e., NBS), Edition (i.e., V1.26), Edition Date (i.e., January 2023) and Name of the classification (i.e., Uniclass). It is important to record this as you will want to know which Classification system the class belongs to as well as the version of the tables as this updates regularly. It is also important to understand that a Classification in IFC is made up of multiple pieces of data is not just a single piece of data.

IFC provides a framework for the objects and how they relate to each other, classifications, like Uniclass, provide a way of further describing the objects using more familiar terms.

The Department for Education also have their own way of identifying different space types beyond just utilising the Uniclass SL Spaces/ locations table. This is referred to as their ADS (Area Data Sheet) reference and is used to define the DfE’s design requirements for each space type. The ADS reference is delivered as a Classification Reference in IFC and is delivered alongside the requirement for Uniclass. The ADS references have been fully aligned, with work carried out between the DfE and NBS. This means that Information Managers can check that a valid code is provided against each Space both for the ADS and Uniclass, and also check that these codes are aligned to each other.

Alignment between the DfE ADS and Uniclass means checking can be carried out to ensure the alignment in models is compliant

Verification

The DfE’s Exchange Information Requirements (supported by the Project’s Information Standard) mean that the information requirements are explicit about what data is required to be provided at each stage. The DfE’s Exchange Information Requirements include detailed lists of acceptance criteria for checking models. This means that model checking rules can be developed and utilised by delivery teams across the whole framework, to ensure the information provided meets the acceptance criteria at each stage.

Alphanumerical model checking aligned to the DfE’s Exchange Information Requirements

A key part of our process at Bond Bryan Digital is to work through information checking ‘cycles’. This enables the model authors to work in bite size chunks rather than having to tackle everything at once.

As part of this workflow, it is important to ensure that things are correctly classified in IFC first. For example, we want to make sure all Doors are a Door entity in IFC. For some items we then go deeper and check its Predefined Type (this is a sub-class of the entity). So, for a Boiler we want to check it has a Predefined Type of either STEAM, WATER or USERDEFINED.

Once we have ensured that the Entity (i.e., Boiler) and Predefined Type (i.e., WATER) have been defined correctly we can then look at the data associated to each entity. This will include data such as the ‘Name’ of the product type, its ‘Description’ and of course its Uniclass classification. For the DfE all entities included in COBie require the use of the Uniclass Pr Products table and for entities outside of COBie they can use a combination of the Uniclass Pr Products and Uniclass EF Elements/ functions tables.

For product types the current downloadable Uniclass tables also now set out alignment to the IFC2x3 schema (ISO 16739:2013). This means that additional rules can now be developed to ensure that appropriate Uniclass codes are used against specific IFC entities. This will further help improve the quality of data within building information models moving forward. In the future, having this alignment will to make it easier for IFC to be more hidden from view, and then all the user has to interface with is Uniclass.

Uniclass alignment with IfcWindowStyle

Model Verification Reporting

Given the DfE’s Exchange Information Requirements are explicit, and the information requirements are aligned to IFC, it allows delivery teams to build consistent model checking rules. This in turn allows consistent reporting to be utilised for all projects using the framework.

To support this process Bond Bryan Digital have recently developed a cloud-based reporting process that allows model authors to see the issues they need to address. This also gives everyone an understanding of progress towards a fully compliant information exchange. Reporting includes summary reports, data visualisation and detailed data reports.

Summary table showing where issues exist in models
Dashboard view of data quality
Detailed view showing PASS and FAIL against individual

COBie

COBie (Construction-Operations Building information exchange) is a subset of the IFC schema specially for collecting information for the purposes of maintenance and operations using a standardised open schema. By providing data in line with a standard schema the setup for output is consistent, irrespective of which tool created the IFC-SPF models. Extracting this information directly from compliant IFC-SPF models makes the production of the federated COBie output, from various model providers, far more straightforward for Information Managers.

The DfE also require the COBie file to be submitted with a COBie Quality Control (QC) Report. The free COBie QC Reporter can be used to check compliance with the COBie schema. This report supports the model checking process that will have taken place before this although the QC report also picks up errors outside of information provided outside of models. E.g., Documents.

COBie Quality Control (QC) Report

COBie satisfies only a small number of information purposes and the spreadsheet format was specially designed for these purposes; therefore, the advantage of starting with IFC (which is much more extensive than COBie) is that going forward the DfE’s information requirements can be further extended to incorporate additional purposes.

Find out more

Uniclass is a unified classification system for the built environment covering all sectors and roles, delivered by NBS.

Uniclass is a way to organise everything required for built environment assets and provide a logical code for each general item, which can be used by anyone to identify and refer to it.

Find out more