Design

BIM model checking

Geometry, information, clashes and design rules checked against the information requirements, with a checking report that says what to correct.

At a glance

B1P Group's BIM model checking verifies that the delivered models meet the exchange information requirements: geometry and levels of development, information content and classifications, clashes between disciplines (clash detection), design and regulatory rules (rule-based checking). The result is a checking report with the non-conformities and the correction requests, for designers and contractors who want to deliver compliant models; acceptance checks on deliveries remain with the client.

Definition

What is BIM model checking?

Model checking is the systematic check of a model against written requirements. UNI 11337-5 distinguishes three levels: internal checking by whoever produces the model, checking by the coordinator on federated models, and independent checking by the client or a third party. Four things are checked: geometry (consistency, level of development, duplicates), information (parameters, classifications, completeness), clashes between disciplines, and compliance with design rules and standards.

A standard that defines model quality does exist: UNI 11337-5 for checking workflows and ISO 19650-2 for deliveries. The acceptance criteria, however, are set by the information requirements of each project.

Deliverables: Checking report with non-conformities classified by severity, list of clashes with owner and status, summary of corrections before handover, reusable checking rules
Standards: UNI 11337-5 (checking), UNI 11337-7 (roles), ISO 19650-2 (delivery), exchange information requirements and the project's BIM execution plan, technical standards covered by rule-based checking
Tools: Navisworks and model checking tools for clashes and rules, parameter checks on IFC and native files, in-house automation for repeated checks; report on a B1P Group template

BIM model checking

What is checked, in practice?

First, formal compliance: files, names, versions, coordinate system, model breakdown as set out in the plan. Then geometry: objects modelled with the right tool, the level of development for the stage, no duplicates and no elements on the wrong level. Then information: mandatory parameters filled in, classifications, IFC property sets. Finally clashes and rules: clashes between disciplines, minimum clearances, regulatory requirements that can be expressed as rules.

Every check has an acceptance criterion written in advance, in the information requirements or in the plan: without a criterion there is no check, only an opinion.

BIM model checking

Who organises rule-based checking, and what does it check?

It is organised by whoever is responsible for the check: the BIM coordinator for coordination checks, the client or its independent checker for the independent check. Rule-based checking (code checking) turns regulatory and design rules into automated checks on the model: minimum heights, clear widths of routes, distances between services, fire safety or accessibility requirements where they can be expressed as rules.

Not everything can be automated: the rules have to be written, tested and signed off by an engineer, and the results have to be read. B1P Group delivers the rules together with the report, so the check can be repeated at every delivery.

BIM model checking

Who needs model checking before handover?

Designers and contractors who would rather find errors before the client does: the check is carried out by someone who did not produce the model, using the same rules from the information requirements that the client will use to accept the delivery. It also helps consortia, where each partner delivers its own discipline and a neutral check is needed before federation.

Acceptance checking remains with the client. For contracting authorities and asset operators we do not check models or evaluate tenders: we support the RUP (sole project manager) and train the people who carry out the checks, as explained on the BIM for clients page. On public works, model checking sits alongside the design verification required by the Code; they are different activities.

Checks

Which checks does a checking report contain?

The structure of B1P Group's checking report, by severity level.

Area	Typical checks	Outcome
Compliance with the plan	File names, versions, coordinates, model breakdown, delivered formats	Blocking if a required deliverable is missing
Geometry	Correct modelling tool, level of development, duplicates, elements on the wrong level, consistency between models	Major and minor non-conformities
Information	Mandatory parameters, classifications, IFC property sets, consistency with schedules	Non-conformities with a list of the objects
Clashes	Clashes between disciplines by system group, tolerances, resolution status	List with owner and due date
Rules	Rule-based checking against agreed design and regulatory rules	List of violations with reference to the rule

Related services

What does it combine with?

Frequently asked questions

Frequently asked questions about model checking

Which quality dimensions does a BIM model check consider?

Accuracy (the geometry matches the design, within tolerance), consistency (the models are consistent with one another and with the drawings), completeness (all the required objects and data are there) and currency (the model reflects the latest revision). These are the four dimensions we use in the report.

How long does a model check take?

From a few days for a single discipline model to two or three weeks for the federated model of a complex asset with rule-based checking. The time is set in the offer, based on the number of models and the rules to be applied.

Do you also check IFC models without the native files?

Yes. Many checks are run on the IFC, which is the format for public-sector deliveries; some, on the modelling itself, require the native file. In the report we state which format each check was run on.

Does model checking replace coordination?

No: coordination solves problems during production, checking documents the status of a delivery. Both are needed; independent checking works precisely because it is done by someone who did not coordinate the model.

Do you check models on behalf of the client?

No. Acceptance checks on deliveries remain with the client and, on public works, with the contracting authority. We check models for those who produce them, before handover, and we train the client's technical staff who carry out the checks.

Contact

Do you have models to check?

Send us the model and the information requirements: we will reply with the checks, the timescale and the cost of the model check.

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