Designing green roofs and/or green walls in large scale projects is sometimes very different rather than using these features in small scale ones. The complexity of a mega project is really high, and designers should respond to many issues at the same time. Meanwhile, applying green roofs and green walls to the projects may increase this complexity and many clients may not agree to that.
One of the most challenging factors is how to design the project to be financially feasible, as the cost of creating greenery will be high. Many of our clients (mostly in Middle East countries) worry about this matter and it is very important for the architect to justify his/her proposal at the very initial process of design.
Another challenge, particularly in arid climates, is how to respond to the water issue. Today in many Middle East countries the issue of water has become a dramatic matter and there are even many limitations of using water, issued from governments. Therefore, applying helpful factors such as Zero Water usage or similar methods of saving water would be very beneficial in this case. In this situation the plant selection and slow water consumption of selected plants are very useful.
The other issue for applying Green Roofs and/or Green Walls in mega projects is maintenance. In Iran, clients and even governments worry about future maintenance requirements for the greenery areas. Due to reasons such as the increasing cost of maintaining the green roofs and green walls, in many projects the future occupants neither accounted nor paid for this issue and with droughts we have observed failing and even dead roofs. In this situation, architects would be better off to calculate the exact cost of maintenance annually or monthly from the initial concept design process and try to design in such a way to have a minimum maintenance plan for the roof and greenery areas.
In my presentation, I would like to share with you my experiences in some megaprojects in which I am involved as a designer and architect.