The general regulations of this paragraph shall apply to all districts unless otherwise stated.

No building shall hereafter be erected and no existing building shall be moved, altered, added to or enlarged nor shall any land or building be used, designed or arranged to be used for any purpose other than as included among the uses listed in this chapter as permitted in the District in which such building or land is located nor in any manner contrary to any of the requirements specified in this chapter.

No building shall hereafter be erected, reconstructed or structurally altered to exceed in height the limit designated for the District in which such building is located.

No building shall hereafter be erected nor shall any existing building be structurally altered, rebuilt or moved nor shall any open space contiguous to any building be encroached upon or reduced in any manner, except in conformity to the yard, lot width and area, building location, percentage of lot coverage by building area and by impervious surface, off-street parking space, off-street loading space and other space and area regulations designed in this chapter for the District in which such building or space is located, subject to such modification thereof and such provision as are set forth in this chapter.

Off-street parking space and off-street loading space shall be provided as specified in this chapter and shall be provided with necessary passageways and driveways appurtenant thereto and giving access thereto. All such parking space and loading space, together with such passageways and driveways, shall be deemed to be required space on the lot on which the same is situated and shall not thereafter be encouraged upon or reduced in any manner except as otherwise provided in this chapter.

No yard or other open space provided contiguous to any building for the purpose of complying with the provisions of this chapter shall be considered as providing a yard or open space for any other building, and no yard or open space on one lot shall be considered as providing a yard or open space for a building on any other lot.

Nothing in this chapter shall be deemed to require any change in the plans, construction or designated use of any building, the actual construction of which was lawfully begun prior to the time this chapter or any amendment thereof affecting the same takes effect and on which building actual construction is completed within one year after such change.

Except as otherwise provided in this chapter, required setbacks along street frontages in residential districts shall be maintained as open space and shall not be used for service of any kind such as vehicle parking, clothes drying, or storage.

Any use establishment in any district shall meet the requirements of the Performance Standards of this chapter.

Only one permitted principal use per lot shall be provided, except as specifically authorized in each zone.