At the time any main building is erected or altered or any new use of land commenced, off-street parking spaces as hereinafter specified shall be furnished with necessary passageways and driveways. All such space shall be deemed to be required space on the lot on which it is situated, and shall not be encroached upon or reduced in any manner. All parking areas, passageways and driveways (except residences) shall be surfaced with a dustless, durable, all-weather pavement, clearly marked for car spaces and shall be adequately drained, all subject to the approval of the Town Engineer.