Which type of water closet is likely to involve higher installation costs due to additional structural requirements?

A wall-hung water closet typically involves higher installation costs because it requires additional structural support to accommodate the weight of the toilet and the water it contains. This type of fixture is mounted to the wall and therefore relies on a sturdy, reinforced framework, usually referred to as a carrier system, that must be installed within the wall. This requires careful planning during the construction or renovation of the space to ensure the wall can support the unit effectively.

In contrast, floor-mounted water closets directly rest on the floor and are secured by simple bolts, necessitating less structural reinforcement. Portable water closets, as the name suggests, are designed for temporary use and do not require any permanent installation or structural support, which keeps their costs low. Dual-flush water closets refer to a type of flushing mechanism that conserves water, but their installation does not inherently require any additional structural considerations compared to standard fixtures. Consequently, the wall-hung water closet stands out for its need for enhanced support systems, leading to higher installation expenses.