If a lot or parcel of land used for a single-family residential purpose is assessed under this section and the lot or parcel of land is subdivided into additional lots for single-family occupancy, the Council may assess the additional lots or parcels of land into which the original parcel of land is from time to time divided on the basis of the average cost as determined under the provisions of this Part at the time the owner of the additional lot requests the utility service. Such assessment shall be made only after the owner of the newly created lot or lots has requested water or sewer service and an assessment against his property or has paid the amount of the assessment in cash. In the absence of such request or payment, the service shall be withheld from the property. If a lot or parcel of land is used for any purpose other than for single-family occupancy, the Council may assess the lot or parcel of land used for such other purpose in an amount equal to the multiple of the assessment for a single-family lot by the nearest number of times that the area so used is divisible by twenty thousand feet but in no case shall the assessment be less than the assessment which would be made against a single-family dwelling lot.