Building Components to Enhance Sustainable Cities

William Whistler
LEED AP, Estidama PQP, Cert. Thermography, Cert A.T. Testing
Managing Director
Green Building Solutions International (GBSI)
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Cultural Heritage

The wealth of several of the Gulf countries has allowed a ten-fold increase of the built environment since the beginning of the twenty-first century; creating contemporary global capitals where residents live, work, shop, travel and recreate in 24/7 air conditioned environments. These 100 percent conditioned environments use massive amounts of energy; estimates routinely range from 60 to 75 percent of domestic and commercial building electrical usage is devoted to air conditioning alone. As an example, the UAE average year temperatures is above 35o Celsius with 350+ annual days of unbroken sunshine. To maintain a typical home in Abu Dhabi, the UAE national capital, at an indoor temperature of 21o Celsius the resulting heat energy that would need to be displaced by air conditioning would equal 2970o annually.

Traditional Methods of Handling the Harsh Climate:

Massive walls to absorb the heat in the day and then re- emit to the outside evenly at night. Using light colors also reflects away move of the sun’s heat energy.

The traditional wind tower uses the natural upward flow of warm air to allow cooler air to replace it at the lower living areas

The shading of windows with open screen work or mashrabiya allows outside views while keeping the inside cool.

Governance and eco-regulations

Today’s green building codes reinforce traditional, regional methods with new information, measuring implements and standards, modern design and materials. Green building is a new term but buildings that conserve energy and stay cool and dry in our desert climate have always been a part of this culture. New codes such as the Abu Dhabi Estidama Pearl Rating System (PRS), The Qatar Sustainability Assessment System (QSAS) and the Dubai Green Building Regulations and Specifications (DGBR&S) differ from green codes in other parts of the world in some very important ways that enhance our local methods of building in our harsh climate. Here are some examples:

(PRS) Cool Building Strategies. This unique credit point specifically rewards the incorporation of passive design measures. Passive design measures are defined as those requiring no mechanical systems and include orientation, shading devices, building fabric improvements such as higher insulation and building envelope air tightness. This regulation helps our buildings reduce the heat load and thus our air conditioning cost.

(DGBR&S) Light Colours on the Outside of Buildings. All new buildings are to have at least 75% of the vertical wall areas be materials that are light enough to reflect away about half of the sun’s heat energy.

(PRS) Outdoor Thermal Comfort Strategy. This mandatory credit requires either man-made or natural shading for a specified percentage of all car parking, public spaces, walkways and playgrounds and allows for additional points for increasing the amount of shading for these areas. These credits are a direct reflection of local environmental conditions.

(DGBR&S) Orientation of Glazed Facades. The design has the option of having either 50% of the windows facing north or treating all south and west windows with shading devices to reduce heat gain.

(QSAS) Local Material Usage. Specifying permanently installed materials that are extracted and manufactured within the region and specifying permanently installed materials that are made from recycled content reduces energy use and waste while enhancing the local community’s resources.

(PRS) Building Envelope Verification. This credit requires on-site and offsite testing building envelope assemblies as well certificates testifying that any building system element has been pre-tested. The inclusion of this credit, while greatly impacting the site inspection process, will help to counteract the current high percentage of local building air and water intrusion problems.

(DGBR&S) Indoor Air Quality Compliance- Existing and New Buildings. This regulation is unique in that it mandates actual on-site monitoring of such common air pollutants such as Formaldehyde, Volatile Organic compounds, Respirable Dust, Carbon Dioxide and Mould. These unhealthy substances in our interior air are both because of natural conditions as well poor building techniques and only get worse over time unless addressed properly.

These images are from the Estidama Pearl Villa Rating System Guidelines. They show how is it important to plan our homes with the local climate in mind to save energy and live comfortably.

Indoor Environmental Quality

The modern building codes newly enacted in the region are helps us build using our historic building knowledge in modern ways. One issue coming to the fore in constructing and maintaining buildings in this region is a focus on the air tightness performance factor of the building envelope. The permeability of the building envelope is directly connected to indoor air quality because un-planned for outdoor / indoor air exchange allows the humid desert air inside where it eventually accumulates in the A/C system.The outdoor of our region air gathers dust, salt and biological spores as it travels the trade currents from distant subtropical land masses and across vast deserts and high salinity bodies of water.

Infrared Camera images showing outdoor air infiltration in various local buildings

This diagram show common areas where a poor quality building shell will allow outdoor air inside

Indoor Environmental Quality

Once inside our building A/C system this unhealthy air is re-breathed over and over again. Without proper system maintenance and regular cleaning of filters and ductwork the accumulation of these airbourne irritants can lead to respiratory problems especially in young children and the older members of our community. Pollutants such as air particulates and mould spores from the exterior air join together with indoor contaminants like Volatile Organic Compounds such as Formaldehyde to produce unhealthy air quality. This concern is specifically addressed in the new Dubai Green Code by calling for monitoring every 2 years.

Our dusty and mould spore laden exterior air can be trapped inside our A/C system unless cleaned regularly.

Governance and eco-regulations

The Estidama Pearl Rating System for Community Development is a particularly good example of how our leaders are working to preserve the natural beauty of the region and guide development so that we do not ruin what we cherish most as we expand and grow.

Three Estidama (PRS) requirements: NS-R1, Natural System Assessment, NS-R2 Natural System protection, and NS-R3 Natural System Design & Management Strategy are all mandatory and taken together represent a much more intensive obligation for project developers and team members in the area of natural species habitation safety than other non-regional green codes. In brief the requirement is to work closely with Abu Dhabi and Federal agencies to identify priority habitats and priority species on the development site. If existing priority natural assets cannot be protected and enhanced on site they must be mitigated for and re-established offsite according to strict guidelines. Whether on-site or off-site, natural habitats must have a filed management plan with a five year funding commitment from the developer.

Estidama (PRS) is also taking a proactive stance in the creation and expansion of the regional environmental systems and habitats with two other credits: NS-3 and NS-4. The NS-3 Ecological Enhancement credit can be obtained by the planting of additional amounts and varieties of native plants. NS-4 Habitat Creation & Restoration allows up to 6 further credits for the additional creation or restoration of habitats. Credits can be obtained by the planting of additional amounts and varieties of native plants all of which will reduce water consumption while promoting the natural beauty of the regional environment.

Community Life

By putting the weight of the law behind these new green building government regulations and other municipalities codes new ways of designs and building are being done and communities as a whole will benefit. Community life in The Arab Towns of the Future cannot be sustained without conservation of the natural resources available that we depend on. Compliance to the new sustainability codes leads us to the conservation we need to continue our prosperous future.

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