For years, the building industry in the Middle East has faced the challenges of large-scale projects and extremely tight programmes. Indeed, the region is recognised for its mega-projects, glazed skyscrapers and cities built from scratch in a matter of decades. A fact that portrays the fast-paced and high-pressured environment is that often the design of the façade is occurring as the foundations are being laid and sometimes even when the structure is being erected!
To be able to deal effectively with such challenges, all the links in the supply chain from design to delivery have had to hone their project management, logistics and problem solving skills to exemplary levels. In addition to this, Dubai has attracted talent and know-how from all over the world establishing itself as an influential design hub for the region and beyond. Contractors are also attracted from Europe, Asia, and Australia adding to the diversity. The benefits of this diverse environment are multiple including a rich variety of perspectives, increased creativity feeding from a global pool of knowledge and a natural inclination to collaborate and establish new partnerships. On the downside, the push for high volume and speed often did not leave enough time to properly address aspects such as sustainability, interdisciplinary integration or quality of construction. This has, however, changed radically in recent years. The construction industry is evolving rapidly driven by the increasing awareness of the importance of sustainable development. Challenging targets such as net-zero commitments are being encouraged by statutory bodies and businesses driving a profound transformation and setting higher standards and expectations.
The objective of this article is to provide an insight to the current trends in the Middle East construction industry with a particular focus on how the operational energy of buildings can be reduced through sustainable design and construction.
What is sustainable architecture?
The UN 2030 Agenda for Sustainable Development issued in September 2015 is a good reference to establish how architecture can contribute to sustainable development. It sets out 17 goals for 2030 covering social, economic and environmental dimensions. Out of the 17, there are four goals that have a direct effect on the building industry and façade design in particular as highlighted below:
• Climate Action – linked to Responsible consumption and production
• Health and wellbeing
• Industry Innovation
In the context of the building industry, the targets within the Climate Action goal can be linked to improvements in the operational energy of buildings while the ones within the Responsible Consumption and Production goal can be linked to embodied energy. Why reducing energy and emissions in building and construction is key in the fight against Climate Change.
The buildings and construction sector are key in the fight against climate change because of its large share in global energy consumption and carbon emissions. As per the Global ABC Status Report it accounts for almost 40% of total energy use and carbon emissions. Moreover energy and emissions of this sector continue to grow despite improvements in building envelopes and systems which are not fast enough to offset strong population and floor area growth. Given the growth in population and buildings, it is pivotal to reduce the operational energy of buildings to, at least, cap the increasing global buildings energy use.
Drivers for reducing energy and emissions
In order to reduce the energy consumption and carbon emissions of buildings, it is necessary to embed sustainability as an integral part of the design and construction process.
Sustainability in construction has been considered for some time now as a “good to have” but perhaps not indispensable. In the last years, however, concerns over climate change have climbed in the political agenda, provoking an increase in the number and thoroughness of policies that enforce energy efficient design. The better-known codes in the region are Estidama (Abu Dhabi), Al Safat (Dubai) and Gsas (Qatar). IBC codes and certification systems such as LEED are also used.
In addition to codes and certifications, guidelines are also being developed to assist the designers and the industry to meet the targets. A recent example as above was in the Middle East i.e. the new Thermal Insulation Guidelines for Residential Buildings in Bahrain that have been developed by AESG in line with the Kingdom’s national plan for energy efficiency and renewable energy. Codes in the region were benchmarked against international codes and certifications such as ASHRAE, BR Part L, LEED, BREEAM, etc. Solutions specifically applicable to the country were studied and developed to produce a set that can be used as a tool to assist designers and engineers in the decision-making process and selection of appropriate façade systems both for new buildings and for retrofits. These guidelines present more than 21 different systems as options to guide project teams during design and construction.
In order to meet the targets set in the Paris Agreement and subsequent UN 2030 Agenda for Sustainable Development, The World Green Building Council has set a route to net-zero carbon that relies on 100% of new buildings operating at net zero carbon by 2030 and 100% of buildings operating at net zero carbon by 2050 . A net zero carbon building is a highly efficient building with all remaining energy consumption from on-site and/or offsite renewable resources.
These targets are truly challenging and will require the joined effort of governments, cities and businesses if they are to be achieved. The UAE is embracing and encouraging this push for change. As per the UAE Vision 2021 and the UAE Energy Strategy 2050 it outlines the evolution that needs to take place to meet this target from compliance with current regulations, through nearly zero energy, net zero energy to arrive to net zero carbon. AESG is a signatory to the World Green Building Council’s ‘Net Zero Carbon Buildings Commitment’. As part of this commitment, we launched a new ‘Pathway to Net Zero’ tool that’s designed to define and evaluate the options available for reducing the embodied and operational Carbon footprint of buildings. This provides our clients with an optional pathway to achieving net zero carbon buildings for every project we get involved with.
There are already a couple of examples of Net Zero Energy projects in construction in the region: The Expo Sustainability pavilion and the headquarter offices for the Dubai Energy and Water Authority (DEWA). Net Zero buildings are designed to work extremely hard: (1) all spaces have an impact on energy consumption. Therefore, the first step is to revisit the architectural brief and remove spaces that are not essential, (2) envelope and mechanical and electrical systems have to be extremely efficient and (3) energy needs to be harnessed from renewable sources such as solar radiation.
Early stage energy optimisation
In the interest of reducing the energy demands of buildings, it is useful to perform optimisation studies. Energy optimisation studies look at improving the performance by making adjustments in parameters such as building
orientation, percentage of vision glazing versus opaque facades, shading configurations or thermal and solar performance of each of the components.
The earlier in the design the optimisation takes place, the greater the effect. Traditionally energy modelling required long simulation time and was carried out once the design was advanced. As a result, there was little room to inform the design. To resolve this situation, strategic energy modelling is being brought to the Concept and Pre-concept design stages. The main focus of this exercise is not accuracy which can be achieved at later stages. Instead, the focus is achieving awareness from the beginning and a coordinated approach between the Architect and Façade consultant/energy modeller.
It is advisable to start by developing a clear modelling plan to remain focussed on the objectives. Every modelling exercise should be run with a clear purpose. A valuable method for decision making is sensitivity analysis of multiple design options to understand what parameters have a greater impact on the performance. At a building level, the parameters that are generally considered are energy transfer through the facade, insolation, potential for Building Integrated Photovoltaics (BIPV) and daylight. At a masterplan level, the elements of study are typically sunpath, sunlight hours (access to daylight), solar radiation analysis (building level), cumulative radiation analysis (public realm) and wind rose (uncomfortable and comfortable winds).
Artificial Intelligence applications in the construction industry
Examples of AI developments such as speech recognition, autonomous vehicles, intelligent routing in content delivery networks or military simulations are staggering. Perhaps the building industry is not quite as developed yet. However, advancements in software are helping automatize the design processes, improvements in computer power are allowing to process the large amount of data that is now available (from weather files to actual live information of buildings that is collected with sensors) and there are even some sophisticated examples of AI involving machine learning and generative design.
Parametric design tools are very useful to speed up the early stage energy optimisation process as described in the previous chapter. Parametric analysis can be conducted to establish ideal and optimised massing configurations, including orientation, heights and positioning of the buildings in the given location and environment. The process allows to analyse how various numerous configurations perform environmentally and provide the design team with the necessary performance evidence to optimise the design. Automated geometry generation methods can also be explored as in the image above
Parametric software can also be used to rationalise free-form geometry. An example can be found in Ciel Tower in Dubai Marina, a 360m high tower by Norr Architects under construction with a glazed curved façade. While fabricating curved glass panels is possible, it is quite expensive. To reduce cost, there is an alternative to fabricate the panels flat and then cold bend them to shape. This has to be done within certain set rules that respond to engineering principles. There is, for example, a maximum curvature that can be achieved without inducing excessive stress on the glass and the structural silicone. This and other structural or manufacturing constraints are then embedded within a script that will generate the geometry. If the allowable curvature is exceeded, the design then needs to be adjusted as required in an iterative process. With traditional tools, this process would be very labour intensive. The benefit of doing this parametrically is that once the script has been generated, subsequent geometry adjustments or options can be explored with minimal additional work. Furthermore, the software allows a large degree of automatization and accuracy in the production of fabrication drawings if required.
Combined with sensors and actuators, AI makes possible the design and construction of intelligent buildings that are responsive to the external and internal environments. It can collect and analyse information related to the temperature, solar radiation, lighting levels, occupancy, air quality, wind speed, etc. and automatically trigger reactions on active mechanisms such as moving shading devices, operable dampers for ventilation or HVAC controls. The effectiveness of the control measures can be monitored through collection and analysis of further data what would allow for an automated learning process. AESG offer a calibration scope where the actual weather and energy consumption is collected and then crosschecked against the design. This is useful to understand if the building is operating as it should and to identify and resolve potential issues.
Building envelope commissioning
The final objective of energy optimisation should be that the final product, the finished building, actually performs to the designed performance. The best way to ensure quality and performance is maintained throughout the building process is through building envelope commissioning which consists of a third-party specific supervision of the elements and processes that affect the final performance of the envelope. This service is contemplated in LEED version 4.
In summary, the building envelope commissioning process consists of (1) defining the weather tightness envelope of the building, (2) setting ambitious but attainable performance targets for each façade type, (3) specifying appropriate control methods such as schedule of testing and inspections, (4) reviewing the contractor’s documentation including drawings, calculations and material submittals and (5) monitoring fabrication and installation through testing and inspections. The final outcome could be jeopardized if any of these steps is neglected.
While designing new buildings to net zero certainly represents a worth aspiration and way forward, it is equally critical to consider ways to improve the performance of existing buildings. This is because the majority of the existing buildings are far away from the end of their design life. They will still be around in years to come representing a large share of the future building stock. Therefore, improving the energy efficiency of existing developments is what could have the greater and more immediate impact on reducing the energy consumption of urbanization. Acknowledgement of this is reflected in the drive by the Dubai Supreme Council of Energy (DSCE) around retrofitting buildings to increase their efficiency.
Most experienced architects will agree that a retrofit is more challenging than a new project. This is because retrofits are subject to more constraints and unforeseeable issues. One of the typical challenges is access to limited amounts of information on existing buildings. The as-built drawings are often not reliable, and surveys do not provide all the necessary information. It is therefore advisable to be cautious in the assumptions and take a conservative approach to structural loading in the proposals. If parts of the facades are being retained, it is important to assess rigorously the relative location of the air, thermal and vapour barriers in the final retrofit build-up as getting these wrong could provoke interstitial condensation. It is also important to ensure that the interfaces are properly designed and inspected.
The enhancement of existing projects should be a continuous endeavour as new methodologies and technologies become available. Retrofitting can pose its challenges but with significant long-term operational cost benefits− not to forget the reduced impact on the environment− so efforts to this end can be completely justified.
This article was originally published in IGS Magazines Spring 2020 Issue: Read the full Magazine here for more thought-leadership from those spearheading the industry
Belarmino leads facade engineering and parametric design at AESG. With a strong academic background in Architecture, environmental design and construction technologies, he brings a unique approach to the construction industry based on care for architectural detail, innovation and providing integrated solutions to complex multidisciplinary issues. He has worked with world-leading architectural practices, contractors, developers and statutory bodies across Europe, America and the Middle East, assisting them to resolve their challenges through technical expertise, problem solving skills and delivery focus.