BIM use cases for public clients 2025

Notes:

• Relevant, general standards and client-specific specifications such as detailed modeling specifications and data structures are usually contractually agreed in the General Specifications section. In the context of this ÖIAV publication, reference is made in particular to the following general specifications:
  • ÖNorm B 1801 series for building construction and RVS 02.01.14 for civil engineering
  • BIM standards such as ÖNorm EN ISO 16739, ÖNorm EN ISO 29481-1, ÖNorm EN ISO 19650-1, ÖNorm A 6241 series
  • In general: Relevant standards
  • Detailed modeling specifications based on general or concrete specifications of the client (note: only on the basis of concrete modeling specifications can the “completeness” of a BIM model be checked depending on the project phase and thus also the planning depth).
• The chapter on project organization and collaboration usually also specifies who is specifically responsible for what. For the purposes of this document, this always refers to the BIM roles and responsibilities in accordance with BIM-scope of works LM.BIM from buildingSMART, which should be defined as the basis for projects with BIM.
• This chapter also specifies the file formats in which documents are to be submitted. For the purposes of this document, BIM models are always in .ifc format for the purposes of this document. Other formats such as native formats (e.g. rvt, smc, etc.) must be contractually regulated or are regulated in the respective general terms and conditions. The transfer of native formats usually only makes sense at the end of the contract. The legibility of BIM models for many years or even decades to come is particularly important for public sector clients, which also operates the systems itself. If native formats are required, all necessary data and configuration files that are required for a loss-free restoration of the native working environment must therefore be transferred in addition to the model data. Other supplementary data formats (e.g. for derivations, exports, etc.) must also be contractually regulated.
  This also includes when which documents or BIM models are to be handed over (either in general terms, e.g. a defined period of time before a coordination meeting, or with specific deadlines in terms of the project schedule or project milestone plan). The handling of the model check (e.g. using a check rule set) should also be specified here.
  Note: For the transfer of data, it is recommended, especially in BIM projects, to set up a project or client-specific data repository (Common Data Environment, or “CDE” for short). This is the only way to ensure that links from the BIM model to supplementary documents remain functional over the project duration or life cycle.
• The use cases section describes which processes and activities are to be carried out in the specific project on the basis of BIM models. Individual use cases may recur in several project phases, even at different levels of detail. This applies in particular to the Use case 03: BIM planning and Use case 04: BIM coordination, which must be run through in every planning phase in larger projects (e.g. preliminary design, design, detailed and implementation planning, etc. in building construction as well as route planning, EIA, submission project in accordance with the Railway Act, Federal Roads Act, Waterways Act, material laws, etc. in infrastructure). The BIM use cases in combination with the expected planning phases and project milestones must therefore also be taken into account for the precise calculation of the planning costs.
  Due to the client-specific differences (especially between clients in the building construction and infrastructure sectors), particular attention must also be paid to the fact that the points often described as the first implementation step in some projects should already be defined as a prerequisite for a use case.
  The following descriptions of the use cases must therefore always be critically reviewed for each client and, if necessary, adapted (as slightly as possible) to the specific project.

It should also be noted that the BIM use cases defined below in connection with costs always refer to building costs or construction costs in accordance with ÖNorm B1801. Building costs or construction costs must not be confused with total project costs, which are usually determined outside the BIM model. Quantity takeoff as the basis for cost determination should be as rule-based and automated as possible in order to increase efficiency. Writing costs back into BIM models is generally not recommended. Regardless of this, cost data is sensitive and may only be transmitted to authorized persons.

Some BIM use cases build on each other or require each other. Examples:

• An assignment of the Use case 21: BIM construction accounting usually also requires the commissioning of the Use case 13: BIM-supported LV creation. In addition, the Use case 21: BIM construction invoicing already Use case 13: BIM-supported LV creation must be taken into account.
• If changes in the construction process are to be expected (especially in infrastructure construction / civil engineering) and the changes are also to be billed as far as possible on the basis of the BIM model, the Use case 17: BIM model changes are commissioned. If this is not the case, it is sufficient to integrate the changes in the Use case 22: BIM as-built documentation for official verification or in the Use case 23 – BIM as-built model.
• When commissioning the use case 19: BIM-supported defect management in construction management, it also makes sense to commission the use case 18: BIM-supported construction supervision.

Other dependencies should also be taken into account. For example, rigid GUIDs or PUIDs are required for use case 21: BIM construction accounting (separately defined “project-specific unique IDs” – necessary as some BIM programs generate new GUIDs with every IFC export). Also in the Use case 10: BIM construction phase simulation, these rigid GUIDsorPUIDs are to be used appropriately.

Furthermore, subsequent changes in the BIM model can result in changes in other use cases. For example, manual steps must also be taken when deriving a bill of quantities from a BIM model. This circumstance must be taken into account when making subsequent changes to the BIM model (especially changes after the BIM has been created).

Furthermore, it must be taken into account that today’s BIM programs still provide incomplete data in many cases (e.g. for areameasurements in accordance with ÖNorm EN 115221-6). Therefore, the results from evaluations must always be checked for plausibility or reworked.

Regardless of when a change is made, responsibility or “sovereignty” over a BIM technical model never changes (unless responsibility is officially transferred). This means that if changes or additions need to be made to a specialist model, either the responsible specialist planner (e.g. integration of links, quality assurance documents, etc.) must be commissioned or a separate specialist model must be created (e.g. for works and assembly planning). [1]

Note:
Throughout this document, responsibilities are defined on the basis of roles. However, it is possible that several roles are assigned to one function or person. For example, it is quite possible for a construction contractor to also have the role of a planner, depending on the order situation.

In general, when awarding contracts for services, care must be taken to ensure that the services of different contractual partners are clearly delineated or that the scope of the contract has been defined (e.g. own cost estimator versus planner; preparation of laser scans for construction supervision by ÖBA or planner, etc.).

With regard to terms and abbreviations, reference is made in particular to relevant publications, especially the BIMcert manual from buildingSMART.

In the interests of a uniform understanding, it should also be noted that the following terms have different meanings:

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1. “Fill characteristics” means filling the characteristics according to the client’s specifications (e.g. according to AIA)
2. “Linking” means specifying a (hyper)link for BIM elements, e.g. to documents from another source (e.g. CDE, project documentation platform, product databases, etc.)
3. “Linking” means establishing the assignability of BIM elements to other data (e.g. via GUID, element numbers, etc.). However, linking does not mean the integration of additional data in BIM technical models.
4. Data integration means the transfer of additional data directly into the BIM technical model

It is also added that the term “definition” always includes a project-specific “definition” when describing the use cases.