A garden on a 60% slope

The roof of the ONGC Headquarters in Dehradun was never meant to be easy ground. Designed by architect Hafeez Contractor, it rises at a slope of sixty per cent. On a surface that steep soil wants to slide, water wants to run and roots struggle to find a hold.

A garden on such a roof has to be engineered before it can be planted. We worked with advanced green-roof systems that hold soil and planting in place on the incline. They manage the flow of water so that rain feeds the planting instead of carrying it away.

The planting itself had to suit a roof as much as a hillside. It needed to stay low and steady in wind, to knit the surface together as it grew and to remain beautiful without constant intervention. On a slope this steep every visit for maintenance is an exercise in care, so the garden was designed to ask for as few as possible.

The finished roof reads as a green landform rising with the building rather than a garden placed on top of it. It is a technically complex piece of work that looks effortless. That, to us, is the measure of it having been done well.