x Abu Dhabi, UAETuesday 25 July 2017

Glass on Abu Dhabi buildings could be limited to 30%

The Abu Dhabi municipality's updated Energy Code could revolutionise the appearance of future building facades.

ABU DHABI // If developers had emulated the country's forefathers, the Corniche would be lined with buildings featuring tiny windows and walls up to a metre thick made of gypsum, stone and coral, all designed to protect interiors from the heat of a harsh desert sun.

With the advent of air conditioning, however, architects began to be able to design more modern, accessible buildings, their indoor spaces flooded with natural light, their sleek exteriors made almost entirely of glass.

Authorities in the capital are rethinking this devotion to the transparent. The Department of Municipal Affairs (DMA) plans to issue new regulations governing all building in the early part of next year.

The updated Energy Code could, according to DMA officials, lead to energy savings of up 70 per cent compared to the manner in which older buildings were constructed, giving designers the opportunity to choose either a prescriptive or performance-based approach to achieving those savings. The prescriptive approach would limit glass to just 30 per cent of a building's facade. Under a performance-based approach, the building can have a facade made entirely of glass - but only if the design team proves it can limit "solar gain" to the level of the 30 per cent design.

"For architects, this is going to be a very serious consideration in their designs," said Arthur Millwood, a consultant at Emirates Glass, a manufacturer based in Dubai.

"I believe other emirates and the other Gulf countries will follow, too," he said.

The Energy Code complements the work of the Urban Planning Council, which in April unveiled the Estidama Pearl Rating System. The Pearl evaluates the "greenness" of communities and buildings according to a number of environmental criteria.

The system has five tiers, or "pearls", each placing increasing demands on developers, for one to five. Buildings in the private sector are required to reach a one-pearl rating, while any new Government buildings must achieve a minimum ranking of two pearls.

Reaching that level would require architects and builders to use efficient insulation methods that would not only reduce heat transfer, but "use less glass on eastern and western facades", said John Madden, a senior manager at the Urban Planning Council.

Experts say it is about time the issue is addressed.

Clear glass is associated with a sleek, modern look, and does allow for plenty of natural light, said Dr Florian Techel, an assistant professor and chair of the school of architecture and interior design at the Canadian University in Dubai.

But it also allows heat in, and substantially increases the demand for interior cooling.

"The building then becomes a giant refrigerator," Dr Techel said.

So widespread has been the glass-building trend that Dr Techel and his students jokingly call the succession of shiny buildings lining Dubai's Sheikh Zayed Road "refrigerator alley". It is the same in Abu Dhabi.

"A lot of buildings, unfortunately, and many of them in Abu Dhabi, are installed with glass ... that does not have very good solar control," Mr Millwood said.

But rather than blaming the material itself, the experts are focusing on how it is used.

"You cannot generally say glass is bad or glass is good," Dr Techel said. "It is what you make of it."

From a building's orientation, to the availability of shading devices and the use of high-tech coatings, he said many factors determine how environmentally friendly a glass-facade building is.

Sadek Owainati, a green-building expert and board member and co-founder of the Emirates Green Building Council, expressed a similar opinion.

"You want to encourage natural light in. But by allowing natural light, you do not want to encourage heat gain or loss," Mr Owainati said.

"There is no limit to finding solutions to challenges," he said, for example, that there are now advanced glass materials that allow the sun's rays in but keep the heat away.

Little can be done to improve the efficiency of the existing building stock. But new government initiatives, if properly implemented, can significantly improve the efficiency of buildings of the future.

The Estidama Pearl system, for example, assesses performance by awarding credits for meeting objectives - about half of them for water- and electricity-saving measures. The other main components in the system are indoor-air quality, materials, and availability of recycling infrastructure.

One way to earn enough points to qualify for the one-pearl ranking in the water category is to install the kind of simple, low-use fixtures that are already the norm in many modern buildings. Achieving a two-pearl rating might also require highly efficient landscaping practices, such as using plants that require little water. To secure the highest rating, a building would need to employ some of the more costly green technologies on the market, such as solar-power generation.

vtodorova@thenational.ae