x Abu Dhabi, UAESunday 23 July 2017

Ancient Arabic architecture may be answer to coping with hot climate

How can we utilise technology to develop an improved mashrabiya while preserving its distinctly oriental character? Researcher find out.

When we think of mashrabiya, the elaborately designed screens used in traditional Arabic architecture, modernity is not the first thing that springs to mind.

But like other traditional architectural solutions, mashrabiya could help us develop more sustainable ways of dealing with age-old challenges such as a hot climate.

Using climate-responsive materials, mashrabiya can be upgraded to combine traditional aesthetics with modern performance.

We too often take a brute-force approach to improving our indoor environments, using artificial lighting and air-conditioning.

While these do the job, studies have shown that qualitative factors such as connection to the outside and variability throughout the day are just as important for comfort and physical well-being.
A modern version of the mashrabiya could be a more subtle way to improve the interplay between a building and its environment.

The challenge of creating a comfortable indoor climate is as old as civilisation itself. Mashrabiya were developed in the Arab world to provide a building’s inhabitants with shade, privacy and a breeze – akin to Venetian blinds, a similar solution popularised in the West.

So how can we use technology to develop an improved mashrabiya that can regulate a building’s interaction with its surroundings to reduce the power needed for lighting and air-conditioning, while preserving its distinctly oriental character?

Working with master’s students on our energy management and sustainability course, we have been exploring novel mashrabiya designs to find an answer.

Traditional mashrabiya block out a lot of light, making them poorly suited to modern demands of comfort and performance.

And because they are traditionally made of wood, stone, or other solid materials, mashrabiya lack the flexibility for daylight management that is characteristic of venetian blinds.

To get around such problems, we have gone back to the drawing board to design a dynamic, zero-power mashrabiya facade that passively responds to its environment and is driven by metal components with surprising properties.

Using shape-memory alloys – metals that can switch between two or more configurations based on temperature – our facade is designed to automatically adapt to the sun’s position without any motorised or active controls, optimising its role as the interface between the outside environment and the building’s interior.

It is structured in three layers. When all three are aligned, the facade blocks 40 per cent of incoming sunlight. By shifting one layer, the fraction of blocked sunlight can be increased to 60 per cent, and to a maximum of 85 per cent when both layers are shifted. We are still fine-tuning the mechanics of moving the individual layers, but our first attempts have been very encouraging.

Once completed, we hope it will serve as an ornamental skin for glass-paned buildings with the potential to significantly reduce the need for indoor lighting and air-conditioning while preserving the view, as well as the variability inherent in natural sunlight.

Combined with modern glazing, it should let occupants experience the variability of the daily solar cycle – making them more comfortable and healthier.

We have all become used to seeing buildings as structures that stubbornly face the elements and use power-hungry technology to adapt themselves to local conditions. But we tend to forget that before the technological revolution of the past century, people around the world found innovative ways of addressing many of these problems.

By stepping back and learning from past solutions, we can make ends meet in ways that make sense from an environmental, financial, and health perspective.

Prof Marilyne Andersen is director of the Interdisciplinary Laboratory of Performance-Integrated Design at EPFL in Lausanne, Switzerland.