In this subtitle the following words have the meanings indicated. “Apartment unit” means a single family housing unit that: is one of multiple units within a building; contains at least one full bath and one full kitchen; and does not contain more than two toilets. “Fixture unit” means the assigned value for a plumbing fixture or group of plumbing fixtures, as set forth in the Commission’s plumbing and gas fitting regulations, that is standardized with a common lavatory having an assigned value of one based on its probable discharge into the drainage system or hydraulic demand on the water supply. “New service” means: a first time connection of a property to the Commission water or sewer system, including: a direct connection of an improvement or building; or a connection of the improvement or building through an existing on–site system; or a new connection or increased water meter size for a property previously or currently served by the Commission if the new connection or increased meter size is needed because of a change in the use of the property or an increase in demand for service at the property. “Property” means an improvement or a building on a lot or parcel of land that contains plumbing fixtures. “Toilet” means a water closet, as set forth in the Commission’s plumbing and gas fitting regulations.