Craig Guthrie and Mary Papaioannou
Planning and designing new cities and public realm spaces that are liveable and responsive to a desert environment poses particular challenges. In this article we discuss some of the passive design strategies that were employed on Middle Eastern projects with which we were recently involved, and how we approached sustainability issues as Australian trained landscape architects working in the Middle East.
The United Arab Emirates has a tropical desert climate with sunny weather and infrequent rainfall. Maximum temperatures from April to September average above 40 degrees, often accompanied by high humidity. In the recent past, the design of many urban projects has responded poorly to these conditions, and has resulted in developments where outdoor comfort is compromised and reliance on internal air conditioned spaces and car transport has risen.
This has come about for a number of reasons – including the UAE’s rapid urbanisation set against a still-developing strategic planning backdrop, and also an attitude that the severity of the natural environment is something that can be overcome by technology and abundant fossil fuel.
Increasingly, however, government and developers have been taking an interest in more sustainable agendas – with many passive design measures being investigated and implemented in projects throughout the UAE to reduce reliance on fossil fuels for cooling, and also to extend the duration of the public realm ‘comfort period’ well into the summer months. Of course, passive design measures are not a new idea in the Middle East. Lessons can be found in the fabric of historic urban settlements in the region where people have been ameliorating microclimatic conditions to create liveable environments based on passive design principles for centuries.
As designers who were new to the region, we were interested in studying and drawing on this tradition and reinterpreting these old lessons to create new places for a new, contemporary society. Our work commenced with investing time to gain a solid understanding of the existing natural systems and landscapes – and our design response included the application of community planning and design principles we were used to working with in Australia. Similarly encouraged to draw on tradition and respond to place, more and more contemporary UAE projects are establishing compact mixed use structures with a high level of public realm connectivity. There are a number of benefits. Opportunities for walking or cycling to a wide variety of destinations are maximised as distances are reduced. This is important when temperatures make outdoor activity very difficult during daylight hours over a significant part of the year.
Local air temperatures (internal and external) can be significantly modified through the provision of shade. ‘Self shaded’ buildings and spaces can be more easily achieved where urban form is compact and streets are narrow in relation to building height. Further shading can be provided through awnings, colonnades and freestanding structures and, when planned in parallel with pedestrian, cycle and open space networks, will provide maximum benefits in locations of high activity.
Configuring and aligning streets, built form and open space to facilitate air flow, especially capturing cooling onshore breezes, can further increase comfort on hot days. On buildings themselves, wind towers are traditional architectural features found in the Gulf, which are used to draw breezes down into buildings. They can also be used to ventilate courtyards and other public realm spaces – and contemporary interpretations are featured in recent developments.
Planting, canopy trees in particular, can also be used to moderate local air temperatures and reduce the urban heat island effect through shade provision, evapo-transpiration and wind control.
However, given the precious nature of water in the UAE, balancing the benefits of planting against irrigation water demand is important. On streets for example it is more beneficial to locate trees on the verges rather than the central median, so that trees provide shade for pedestrians as well as amenity.
Carefully located water features can improve thermal comfort through evaporative cooling created by breezes as they blow across the water body. Water features should be small in size and shaded in order to minimise water loss and positioned to provide maximum human interaction.