Entitlement decides the bill, use decides the wear
Contributions to an owners corporation are usually calculated from unit entitlements recorded on the strata plan, which reflect relative value rather than traffic. A small showroom unit and a large storage unit can generate wildly different volumes of vehicle movement while contributing in a fixed ratio that has nothing to do with either. Nobody has done anything wrong here. The arrangement simply was not designed to track wear, and no amount of goodwill at a committee meeting will make it start doing so.
The practical answer is not to redesign the contribution model, which is a matter for the scheme's own records and whatever advice its strata managing agent gives. It is to make the cleaning cost visible enough that owners can see what they are actually funding. When a quote separates driveway sweeping from bin bay work and from the front entry, the committee can discuss the parts that genuinely differ between years instead of arguing about one lump figure nobody can break down.
