Complex sentence: The buildings were limited to 150 feet by law, which was favored by architects and planners who saw the towering skyscrapers of the east coast metropolises as unsustainable and not conducive to the Southern California lifestyle.
Split into simpler sentences: The buildings were limited to 150 feet by law. Architects and planners who favored this regulation saw the towering skyscrapers of the east coast metropolises as unsustainable and not conducive to the Southern California lifestyle.