Green-canopy pergola, Godrej Properties

Godrej Properties wanted shaded parking under a living canopy at one of its sites in Mumbai. The answer was a pergola whose horizontal members hang from their posts on stainless ropes, with climbing plants trained across the top. Acier designed, supplied and installed the ropes and fittings, and the planting was done by the project's landscape contractor. The pergola was completed in 2019.

A pergola over parking needs clear space below for cars, so posts must be few and the horizontal members long. Those members also carry climbing plants, whose weight grows as the canopy matures and rises again when the leaves are wet after rain. A member supported only at its ends has to be deep and heavy to stay level, which adds cost and makes the structure look bulky under the green. Mumbai's sea air and monsoon also call for materials that will not rust.

Each horizontal member hangs from its posts on two tensioned ropes, one at the centre and one at the end. Two suspension points spread the load along the member, so it stays level and can be lighter than a member spanning on its own. The ropes also keep the structure slim, so the planting is what people notice.

The Ø10 mm ropes are AISI 316 stainless tension members: they hold the structure from the top and on the diagonal. Turnbuckles set the tension in each rope, and clevis ends make the connections at the posts and at the hung members. AISI 316 is the marine grade of stainless steel, which suits an outdoor structure in Mumbai exposed to sea air, rain and irrigation water.

The parking now sits under a green canopy that gives shade and grows denser as the plants mature. Cars park in the shade, and from above the parking reads as planting rather than roofs and tarmac. Because the ropes carry the structure, the posts and members stay slim, and the green is what people see.