Awnings and pergolas need to extend beyond the width of the north facing opening by the same distance as their outward projection. 遮阳棚和植被凉棚需要伸出比北向的开口更大的宽度,保持它们向外开启的同等距离。
Pergolas covered with deciduous vines provide self adjusting seasonal shading. 植被凉棚带有每年落叶的藤蔓,成为可自我调节的季节性的遮阳设备。