Practical Considerations for Integrating BIM and Building Control
Demonstrating Building Control compliance can quickly turn into a panicked search for information and tangled mess of paperwork. Fortunately there is a solution: Building Information Modelling. By its very nature BIM lends itself to supporting Building Control, which is the process associated with demonstrating compliance with building codes. There are incredible benefits to be gained by aligning BIM and Building Control. However, to make this an effective and efficient relationship there are a number of factors that require consideration.
Planning BIM and Building Control Integration
The first step is actually making the decision to integrate BIM and Building Control. While Building Control administration and compliance are specialties within construction, the information required is directly or indirectly related to other design and construction processes. For example, project documentation (drawings, schedules, etc) is obviously needed for a variety of project uses, including Building Control. Leveraging Construction Design and Management (CDM) or construction sequencing models to support inspection planning and execution is an example of information re-purposing for Building Control, which is a bit less overt.
Related to is the need to identify relevant BIM outputs for specific Building Control activities. For example:
What documentation is to be generated?
What supporting visualisations or simulations are to be created/utilised?
What data needs to be extracted?
Specific Building Control document sets will need to be produced, however, consideration should be given to deliverables that can be re-purposed. Timing of deliverable production is a potential challenge that would need to be addressed in an information delivery plan.
Sound information management plays a key part in maintaining an accurate and retrievable Building Control information audit trail. This includes storing the relevant revision of native model files used to generate Building Control outputs, along with certificates, inspection records, and supporting documentation.
Building Control Modelling
Once the scope of integration is understood, developing a method for aligning regulations with model objects data is needed. Incorporating different BIM uses can have an impact on model development. This is the case for Building Control and a few questions to ask are:
Is the requirement parametric?
Can the requirement be validated with a rule-based model checker?
Should the requirement be modelled within or as a separate object?
Should the requirement be included as an object attribute?
Different projects or contexts may result in different approaches, but the main goal here is to have a plan for capturing and subsequently communicating Building Control information. The following suggestions can serve to kick start thinking about model production for this purpose:
Model critical constraints
Constraint modelling supports automated and visual compliance checking exercises and also helps implement a clash avoidance approach to coordination. Dimensional constraints such as clear widths and head room are examples of critical constraint modelling.
Include all relevant parameters
Data that validates and demonstrates regulation compliance should be added to model objects. For example, if modelling a critical constraint such as fire stopping was undertaken, adding a label parameter could be used to align with or potentially link installation and inspection records.
Model systems as they would be constructed
This principle has implications across many potential BIM uses, including Building Control. Providing visualisations to align with the focus of a scheduled inspection is an example of a Building Control BIM use that benefits from Virtual Design and Construction modelling techniques.
Pre-construction Model Checking
Comprehensive model quality control procedures incorporate automated and visual checking as good practice. Rules-based applications, such as Solibri Model Checker, are suited well for Building Control compliance checking. Statutory requirement can be aligned with checking rules and report model compliance failures.
The complex nature of construction project requires industry professionals to manually view building systems in context to ensure performance requirements will be met. While energy models produce simulated performance results, people still need to assess the results and identify the knock-on impacts of decisions. Automated model checking can provide the hard data that professionals can use along with their understanding of the nuances associated with Building Control to ensure projects comply with regulations.
Model quality significantly impacts the ability to check models for Building Control compliance. If the model methodology does not consider Building Control uses, automated compliance checking will be challenging. For example, rules-based applications depend on conditional relationships. If the horizontal distance between two objects defines an escape route or an accessibility requirement, the two objects need to be modelled in accordance with the ruleset parameters. If automated results cannot be trusted, then more time is required to undertake manual model checking.
Support for Installation and Site Inspections
Project scheduling, progress tracking, and constructability simulations can benefit the Building Control process in a few ways. Planned inspections can be added to project schedules and associated simulations as tasks. If progress is being tracked and project schedules updated accordingly, work that is at risk of being incomplete for a planned inspection can be highlighted in advance.
Construction visualisations and simulations can be used as part of the model compliance checking process and provide guidance to ensure building systems are installed to comply with regulations. Specific regulations can be highlighted in a visualisation or simulation to confirm Building Control requirements. The as-built condition can be compared to the model or construction sequencing to ensure the work is compliant with associated regulations. Any lessons learned from the as-built / as-modelled comparison can be used to update construction methodologies that better address regulation requirements. This constructability visualisation and simulation use case can potentially be enhanced through virtual and augmented reality technology.
Non-compliance with Building Control regulations is a significant project risk that can prevent the completion and occupation of a building project. Construction visualisations and simulations can help mitigate this risk by supporting pre-inspection activities. The project team member or third-party certifier can use the information to prepare for inspections and maximise time on-site. As with other aspects on integrating BIM and Building Control, model quality is critical. If the as-built condition does not reflect the model or sequence of works, the value of using BIM to support inspections is reduced.
The primary purpose of Building Control is public safety. Compliance with relevant regulations has to be the number one Building Control priority for project teams. However, the project delivery risks associated with the Building Control process also need to be addressed. Both of these priorities can be aided by integrating BIM and the cost of achieving these benefits would need to be assessed. Key points that inform the value assessment include:
Project team capabilities
The skills and technology available to the project team will help determine the level of BIM / Building Control integration that is possible. If a project team doesn’t have the experience, software, or hardware to efficiently produce construction simulations, it is not practical to incorporate them into Building Controls processes. Project team capability is the primary factor in developing a value proposition for integrating BIM and Building Control.
Some methods for integrating BIM and Building Control require additional modelling. Firestopping is an example where effort is required to model and coordinate a scope of work that may not be explicitly required by an employer. The effort required to produce firestopping model information needs to deliver a benefit to the project team. Computational modelling techniques like Dynamo can help with the heavy lifting, but additional effort is still required. If models will be used to communicate firestopping requirements or support firestopping inspections, then there is a benefit in mitigating project risk and streamlining inspections that would need to be weighed against the cost of model production.
Identifying Building Control use cases for existing models and deliverables improves the value proposition for integrating BIM. However, there may be additional work required to enhance an existing model for Building control uses. For example, a constructability simulation used for site logistics will require a more detailed approach for a Building Control constructability simulation. While enhancing an existing simulation methodology may only require minor adjustments, the time needed to revise and manage the new level of simulation should be considered.
Automated checking opens up a number of possibilities for integrating BIM and Building control. The time required to establish and test model checker rulesets should be considered. Time also needs to be allocated for reviewing model checking results.
One more thing…
Integrating BIM and Building Control processes is a use case that teams should consider during project planning stages. Building Control risk mitigation can be aligned with other project activities and addressed over a project lifecycle through BIM. The effort required to integrate BIM and Building Control does need to be assessed against its cost, which will primarily be driven by team capabilities. While the technology required to integrate BIM and Building Control exists, new tools and approaches keep this topic open for future consideration.