Typically, the wall framing elements such as studs are not modelled which makes them invisible to clash detection checks. If it doesn't exist in the model, you can’t check it. But once on site, it is common to find wall framing elements clashing with services (ventilation, pipes, electricity). This results in additional costs to fix the frames and relocate the services, delaying the construction process.
Currently, to identify these issues, designers either have to do a visual inspection of the models, or they have to model the framing elements hidden within the walls. In either case, every single opening must be checked manually, which is a very time-consuming process considering that large buildings may have hundreds of openings to check.