LCZs 1 to 3 are characterized by tightly packed buildings and little green space.

LCZ 1:  Compact high-rise

• tightly packed buildings to tens of stories tall
• few or no trees
• little or no green space
• concrete, steel, stone and glass construction materials
• small diurnal temperature range

LCZ 2:  Compact mid-rise

• tightly packed buildings of 3 to 9 stories tall
• few if any trees
• little or no green space
• stone, brick, tile and concrete construction materials
• small diurnal temperature range

LCZ 3:  Compact low-rise

• tightly packed buildings of 1 to 3 stories tall
• few or no trees
• little or no green space
• concrete, steel, stone and glass construction materials
• diurnal temperature range is medium

Source:  Stewart and Oke (2012)