Sustainable Airport Terminals: Design principles to support a more sustainable future

SUSTAINABLE AIRPORT TERMINALS

Design principles to support a more sustainable future

Author: Massimiliano Martinenghi Scott Brownrigg

INTRODUCTION

RETHINK

2.1 Streamlining the journey

2.2 Harnessing natural ventilation

2.3 Luggage delivery services

2.4 Multi-modal interchange

2.5 Future-proofing

REDUCE

3.1 Materials

3.2 Noise

REUSE

4.1 Existing structures

4.2 Flexible design

4.3 Operational resilience

CONCLUSION

Entrance of Istanbul Airport © Jim Stephenson 2019

INTRODUCTION

In an era marked by climate change and growing concerns over resource depletion, the pressure is on to explore new terminal design solutions in order to achieve a reduction of 45% by 2030 and net-zero carbon by 2050.

The principles of ‘the three R’s’ "Rethink, Reduce and Reuse" have emerged as fundamental tenets of sustainable development. These three simple yet powerful words encapsulate a holistic approach to addressing some of the most pressing issues driving the future of terminal design.

Designers need to consider ‘the three R’s’ to achieve significant reduction to carbon emissions and collaborate on the target for global warming reduction.

RETHINK

The aviation industry has long been a symbol of human progress, connecting places and cultures. However, this progress has come at a significant environmental cost, with aviation being a major contributor to greenhouse gas emissions. The first step towards a sustainable future involves re-evaluating and re-thinking our design approach and consumption patterns.

This means questioning our choices and rules, pondering the necessity of energy intensive design, and considering the impact on the environment. By fostering a culture of mindfulness, we can make informed decisions that prioritise sustainability processes, opting for eco-friendly alternatives.

Perhaps the most significant aspect of rethinking sustainability in passenger terminal design is a shift in mind-set. Examples of how we can rethink passenger terminal design to help airports meet ambitious sustainability goals and carbon reduction targets in line with international agreements include:

Scott Brownrigg proposals for Heathrow West’s T6 © Scott Brownrigg

Inter Terminal Plaza at Heathrow West T6 © Scott Brownrigg

2.1 STREAMLINING THE JOURNEY

Optimising the footprint of a terminal can reduce walking distances for passengers, the need for mechanical transportation systems, and energy consumption. The embodied carbon within the structure and foundations of a building can make up to 60% of the total building, so reducing the overall footprint and area by 4,000 sq m per MPPA would create a 30% reduction in embodied and operational carbon.

A well-designed and efficiently organised terminal can streamline airport operations; making it easier for airport staff to manage passenger flows, security, and baggage handling efficiently. Minimised congestion can enhance overall passenger experience, facilitating improved wayfinding, accessibility, and shorter transfer times.

How a more streamlined approach to terminal design would work with current terminal business models, which often encourage duty free shopping to slow people down, would need to be carefully considered. It is worth noting that dutyfree purchases create additional weight on aircrafts and therefore increase fuel consumption

2.2 HARNESSING NATURAL VENTILATION

Embracing natural ventilation can help to minimise the use of mechanical ventilation and therefore, energy consumption associated with the operation of passenger terminal buildings.

Designing passenger terminal buildings with natural ventilation can offer an innovative and sustainable approach. This is logistically dependent, however, on the adoption of cuttingedge technologies by the wider industry to address air and noise pollution currently produced by aircraft.

Aircraft noise is a significant issue that affects passenger comfort and the overall airport environment. Terminal buildings designed for natural ventilation would allow more noise to enter the terminal, which can be a source of inconvenience and stress for passengers. This could be addressed if new fuel technologies come into use.

Aircraft engines emit various pollutants, including nitrogen oxides (NOx), carbon monoxide (CO), and volatile organic compounds (VOCs). With many passenger terminals located within close proximity to runways and taxi-ways, these emissions are degrading air quality in and around the terminal area.

Stricter environmental regulations have pushed for the development of engines that produce fewer emissions. Engine designs incorporating advanced combustion techniques, like lean-burn and low-emission combustors, help reduce nitrogen oxides (NOx), carbon dioxide (CO2), and other pollutants. However. the introduction of new electric or hydrogen aircraft engines could eliminate both air and noise pollution allowing us to re-think the way passenger terminal buildings are designed.

Designing passenger terminal buildings with natural ventilation involves using elements such as wind and thermal buoyancy to provide fresh air and maintain comfortable indoor conditions, reducing dependency on mechanical systems.

This offers several advantages; properly designed natural ventilation systems can ensure passenger comfort by regulating temperature and humidity. Integration of natural elements into terminal design, such as natural light and airflow, creates a more pleasant and calming environment, reducing stress for passengers.

2.3 INTRODUCING LUGGAGE DELIVERY SERVICES

Another example of re-thinking passenger terminal design is to remove the Baggage Handling System (BHS) - a radical idea that could significantly transform the airport operational and design paradigm.

Relocating the BHS system outside of the terminal and implementing a delivery, and collection procedure similar to those used by large distribution companies, would free up a significant amount of space. Leading to faster

and more convenient check-in and bag drop processes, and a more simplified and flexible terminal design. This in turn, makes development more straightforward and cost-effective in the future. Crucially, space savings can be quantified in terms of both embodied and operational carbon savings.

The ‘luggage delivery service’ may appeal to a broad range of travellers, but is likely to be particularly attractive to those seeking a

seamless and efficient travel experience. Eliminating the need for passengers to check-in their luggage at the airport and wait for it at baggage reclaim hall.

There are of course challenging aspects that would need to be addressed such as logistics, customs, and security regulations. It is also important to recognise the need to address a potential increase in emissions associated with moving luggage separately to passengers.

Any changes to baggage handling procedures must align with international aviation standards and regulatory requirements as defined by ICAO. Luggage delivery services would require careful coordination between airlines, airports, logistics companies, and transportation providers to ensure a smooth and reliable process.

ABOVE: Section through the Baggage Handling System at Heathrow West © Scott Brownrigg

2.4

MULTI MODAL INTERCHANGES

Re-thinking connectivity between future airport terminals and public transport including buses, trains, and subways is essential to facilitate seamless transition and multi modal interchange. Thus encouraging passengers to choose eco-friendly transportation options when travelling to and from the airport.

A multi-modal Interchange is a crucial element in modern airport design. By facilitating seamless integration with public transportation systems, airports can significantly reduce their

environmental impact, alleviate road congestion, and enhance passenger mobility.

A multi-modal interchange reduces the number of individual vehicles on the road, thereby decreasing greenhouse gases and air pollution associated with airport access. It can also help reduce road congestion, which is a common issue around major transportation hubs. Not only benefiting passengers, but also local communities.

TUBE TRAIN

2.5 FUTURE-PROOFING

Future-proofing a terminal reduces the need for frequent renovations and associated resource consumption. Designing terminals with flexibility in mind to accommodate future technological advancements and changes in passenger preferences will become more common.

This concept of ‘future-proofing’ terminal design is becoming increasingly important as technology and passenger needs evolve. The functional requirements for airports are constantly changing which subsequently creates

a need for frequent renovation and extension.

Reducing the need for renovation minimises resource consumption, construction waste, and associated environmental impacts. It aligns with sustainability goals and reduces the carbon footprint of airport operations.

ABOVE: Heathrow West T6 Inter-Modal Interchange diagram © Scott Brownrigg

In the context of sustainable architecture, the concept of ‘reduce’ is a fundamental principle that pertains to the field of conservation of resources, waste reduction, and the minimisation of negative environmental impacts.

This can be achieved through conscious efforts to conserve energy, cut down on water usage, and adopt building scale optimisation. Within the aviation sector this concept focuses on minimising the industry's contribution towards greenhouse gases, noise pollution, and resource consumption through the adoption of cleaner technologies, and making energy-conscious choices. Examples of how the reduction concept applies to sustainability in the aviation sector include:

Scott Brownrigg proposals for the expansion of Media Airport © Scott Brownrigg

3.1 MATERIALS

Reducing resource consumption is a central tenet of sustainability. This involves using fewer natural resources, such as water, energy, raw materials, and non-renewable resources in production processes and daily activities. Sustainable practices aim to optimise resource use to minimise waste and environmental degradation.

In contemporary aviation infrastructure, concrete reigns supreme for ground service roads and slabs on grade, as well as the airside. Its dominance stems from a multitude of advantages: durability, strength, resilience against environmental elements, coupled with low maintenance demands, enduring longevity, favorable cost-effectiveness, and swift construction timelines. These attributes collectively position concrete as the premier choice for critical infrastructure construction.

Optimising terminal design can help us minimise concrete and foundation requirements alongside the demand for raw materials, such as aggregates and cement, which are finite resources extracted through energy-intensive processes. Reducing the terminal footprint by optimising the design and minimising concrete and foundations can result in substantial cost savings too.

However, contemplating beyond mere concrete volume reduction opens avenues for integrating alternative, sustainable materials and systems like steel and timber. Embracing such alternatives not only diversifies construction materials but also holds promise for substantial resource reduction during the terminal building's construction phase.

Proposed timber lattice roof for an airport in Saudi Arabia © Scott Brownrigg

3.2 NOISE

Aircraft noise is a concern for the environment surrounding a terminal. Sustainable aviation practices include reducing noise pollution through the development of quieter engines and aircraft designs, such as the implementation of highbypass turbofan engines, adaptive propulsion systems, and innovative materials to reduce engine noise during take-off and landing.

These technologies are fast developing and are likely to be implemented soon, with quieter electric or hydrogen engines that will minimise noise pollution. When noise is no longer a problem, we can rethink the current concealed box that is terminal design into something different. A reduction in noise improves the quality of life for nearby residents addressing one

of the most critical aspects for the proximity of airport to residential areas.

Noise reduction at airports is a multi-faceted challenge that requires a combination of technological innovation, infrastructure changes, and community engagement.

Some advanced technologies are already available and include ANCS (Active Noise Control Systems) which work using active noise control technologies within airport terminals and surrounding areas. These systems utilise sensors and speakers to produce sound waves that cancel out specific frequencies, effectively reducing the overall noise level.

Aircraft engine development has also seen significant advancements over the years, driven

by the continuous pursuit of improved efficiency, reduced emissions, and enhanced performance. High-bypass turbofan engines, for example, are now widely used in commercial aviation for their fuel efficiency.

The integration of landscape design with noise reduction strategies can effectively minimise the impact of aircraft noise on neighbouring communities while simultaneously enhancing the overall aesthetics and functionality of the airport surroundings.

Green belts and the construction of landscaped berms or mounds around the airport area can help absorb, refract, and block the transmission of sound waves from aircraft ground operations toward nearby neighbourhoods. With soundabsorbing properties that can help in dampening

and diffusing noise, introducing water elements such as ponds can also contribute to noise reduction onsite.

Integrating landscape design into airport environments necessitates tailored approaches to mitigate the adverse effects (AE) of bird strikes. The diversity of land uses surrounding airports can either harbour or deter hazardous wildlife, influencing bird strike rates. Unlike homogenous landscapes, diverse surroundings offer a broader array of resources for wildlife, potentially attracting or dispersing bird populations in ways that impact aviation safety. Thus, strategic landscape planning becomes imperative for minimising the risks associated with bird strikes while fostering a harmonious coexistence between airport operations and surrounding ecosystems.

Landscape design at Heathrow West © Scott Brownrigg

REUSE

Reuse is about extending the lifespan of products, materials, and resources. It involves re-purposing or repairing items instead of discarding them. By promoting a culture of reuse, we can reduce waste, conserve resources, and minimise the demand for new products.

Architects often explore the ethical dimensions of reusing materials and resources. Reuse is seen as a moral imperative within the framework of sustainability because it aligns with principles of responsible resource management, reducing over-consumption, and minimising harm to the environment. Ethical discussions may revolve around questions of social responsibility and inter-generational justice, emphasising the importance of reusing to benefit both present and future generations.

The concept of a circular economy, which prioritises reuse and recycling over linear consumption and disposal, is a topic of interest in the aviation sector. Designers and constructors may explore the ethical and societal implications of transitioning to a circular economy, including the potential benefits for sustainability and resource conservation.

The concept of reuse in the aviation sector, specifically in the design and construction of passenger terminal buildings, could involve the utilisation of existing structures, materials, and resources to create functional and cost-effective airport terminals. Reuse is a critical aspect of contemporary architecture and future terminal design considering the following processes:

Medina Airport Terminal 1 © Yercekim Photography

'Modular steel palm

4.1

EXISTING STRUCTURES

Reuse refers to using an item or material again for its original purpose or function without significant alteration. It involves extending the life of an object or material in its current form. On the other hand repurposing involves taking an item or material and altering its intended use, often creatively, to serve a different function or purpose. It goes beyond the item's original design and intended function.

Both practices contribute to sustainability and resource conservation by extending the useful life of objects and reducing waste, but they do so in slightly different ways.

Reuse is a system that entails adaptability, modularity or prefabrication, as the elements that compose the system can be re-used, modified, moved or re-assembled somewhere else. Airport components such as security equipment, BHS carousel or conveyors, dry partition elements; but also materials can be dismounted and relocated or re-used somewhere else. In a more radical vision, structural elements and every kind of element that compose the building could theoretically be disassembled and reassembled elsewhere.

Re-purposing or applying an adaptive reuse requires the designer to consider providing a new use or meaning to the object. For example older structures or buildings that can no longer serve modern airport purposes, due to an obsolete structural grid, non-compliance with current codes and legislation, or an old layout that no longer aligns with passenger need, can be repurposed into something else.

palm columns inside Medina Aiport Terminal 1 © Yercekim Photography'

CASE STUDIES:

Croydon Airport, London, UK: Croydon Airport was London's main airport before Heathrow Airport. After its closure in 1959, the site was repurposed for various uses, including industrial and commercial developments. However, some of the original airport buildings, such as the control tower and terminal facade, have been preserved and converted into museums and offices.

Tempelhof Airport, Berlin, Germany: Tempelhof Airport, once one of the world's oldest operating airports, ceased operations in 2008. It was then transformed into a public park known as "Tempelhofer Feld." The expansive open space is now used for recreational activities such as cycling, picnicking, kite flying, and community events.

Kai Tak Airport, Hong Kong: Kai Tak Airport served as Hong Kong's main airport until 1998 when it was replaced by the new Hong Kong International Airport at Chek Lap Kok. After its closure, the site was redeveloped for various purposes, including a cruise terminal, residential buildings, and a park. The former runway has been partially preserved as a public park, providing panoramic views of the city skyline.

Stapleton International Airport, Denver, USA: Stapleton Airport in Denver, Colorado, was replaced by Denver International Airport in 1995. The site underwent extensive redevelopment, including the construction of residential, commercial, and retail spaces, as well as parks and recreational facilities. The Stapleton neighborhood now features a mix of housing, schools, businesses, and green spaces.

Meigs Field, Chicago, USA: Meigs Field, a small airport located on Northerly Island in Chicago, was controversially closed in 2003. The site was subsequently transformed into a nature park with walking paths, gardens, and wildlife habitat areas, providing a green space for city residents and visitors.

Airport House, Croydon © dgeezer via Flickr

4.2 FLEXIBLE DESIGN

Designing airports with a flexible layout and adaptable infrastructure is crucial. This allows for easy reconfiguration and expansion to accommodate changing needs, such as shifts in passenger volumes, technological advancements, or alterations in aircraft sizes and types. Terminals can be modified, reused as needed without the constraints of a new build.

Flexibility is mainly about short-term, reversible, and generally small-scale adjustments. Adaptation on the other hand has the inherent capacity to enable longer-term, larger-scale alterations of greater magnitude. Adaptability often implies anticipating and planning ahead to allow for contingencies, while flexibility can be more immediate and situational.

Adaptation and retrofitting in architecture are essential concepts that involve making changes or improvements to existing structures to meet contemporary needs, enhance sustainability, and extend a building's useful life. Necessary modifications and retrofitting are performed to bring the existing structure up to code and to align with current design and operational requirements.

Modularity is also of paramount importance when considering the concept of reuse, referring to the design and construction of buildings using standardised, interchangeable units or components that can be easily assembled, disassembled, or reconfigured to accommodate various needs and functions in the future.

Here are examples of flexibility and adaptability and their impact in future terminal design:

• Plug-in: refers to the potential of a space to grow and transform by adding a new component or module, either horizontally or vertically. Terminal expansions often use this strategy to expand the current footprint area. Plug-in systems are normally of relatively small scale and represent prosthesis added to the building. It could be an extension to the pier or to the main terminal building.

• Connect & add: enables the connection of adjacent spaces to form a single entity or vice versa. Similar to plug-in, the connection is the link between elements. Designing structures with an emphasis on connectivity and modularity enables the integration of new elements seamlessly. Elements are planned and constructed to easily connect with existing architectural features, allowing for smooth expansion or modification.

• Swing spaces: are spaces shared by two functions that can serve either. Functions can adapt over time to meet current needs. Swing gates in departure halls or swing baggage reclaim areas that could work for both domestic and international departure/arrival are examples of swing spaces within the terminal building. Based on specific peak hour demand and airline schedules, these spaces could be used for different purposes and be modified through simple elements such as movable partitions to create an optimised terminal building.

• Movable partitions/furniture or folding elements: are elements that can be easily rearranged to accommodate different functions. Stored, assembled and disassembled, they can modify the layout configuration of spaces based on need.

• Unlabelled or contingency spaces: is a space where the designer has not fully determined its function. Providing the opportunity for the user to define it based on the building's operation time or future needs.

4.3 OPERATIONAL RESILIENCE

Ensuring the operational resilience of the airport during development works is essential for re-use/re-propose.

The operational resilience of an airport during development work is a critical consideration to ensure that essential airport services continue to run smoothly while construction and improvement projects are underway. Maintaining operations during these times is crucial to

minimise disruptions to passengers, airlines, and other stakeholders. Some key factors and strategies that contribute to operational resilience during airport development includes a wellconsidered phase expansion plan, incorporation of soft zones within the terminal layout to allow for change of functionality, and the potential temporary re-routing of passenger flows.

“

Adaptability classifies as the existing ability to adapt, adjust, and change based on different aspects, where elements can be configured, allowing changes in spatial, functional, and technological components without requiring significant disruptions of a building.

(Nakib, F. Towards an Adaptable Architecture: Guidelines to Integrate Adaptability in Buildings)

Proposals for the expansion of Medina Airport © Scott Brownrigg

CASE STUDIES:

Amsterdam Airport Schiphol, Netherlands: Schiphol Airport has a modular terminal design that allows for easy expansion and adaptation to changing passenger volumes. It features flexible gate layouts, movable walls, and plug-in facilities that can be adjusted to accommodate different aircraft sizes and operational requirements.

Singapore Changi Airport, Singapore: Changi Airport is known for its innovative terminal designs and continuous upgrades. The airport incorporates flexible spaces, movable partitions,

and swing spaces that can be reconfigured to accommodate different functions, events, and passenger flows. Changi's terminals also feature plug-in facilities for easy installation of new amenities and services.

Denver International Airport, USA: Denver International Airport has implemented a flexible terminal layout and modular construction techniques that allow for easy expansion and retrofitting. The airport's main terminal includes swing spaces and movable partitions that can be adjusted to accommodate changing passenger demands and operational needs.

Pier 6 at London Gatwick

Helsinki Airport, Finland: Helsinki Airport has embraced a flexible and adaptable terminal design that allows for easy expansion and retrofitting. The airport features movable partitions, swing spaces, and plug-in facilities that enable quick adjustments to accommodate changing passenger volumes and operational requirements.

Gatwick Airport, UK: Gatwick Airport has introduced flexible gate layouts and modular terminal designs to improve efficiency and adaptability. The airport has also implemented plug-in facilities for easy installation of new

technology and amenities, as well as swing spaces that can be used for temporary functions or events.

These examples demonstrate how airports are incorporating flexibility, adaptability, and innovative design features to improve efficiency, accommodate growth, and enhance the passenger experience. By implementing plug-in capabilities, connect-and-add concepts, swing spaces, and movable partitions, airports can effectively manage changing demands and stay competitive in the evolving aviation industry.

CONCLUSION

It is clear that a holistic approach teamed with collaboration and continued innovation are the key ingredients required to make meaningful change. As architects, it is crucial that terminal designs are environmentally responsive and future proofed with the ability to easily adapt to meet changing passenger needs, accommodate new technology, and enable expansion.

By considering how we can rethink, reduce, and reuse in all aspects of terminal design and operation, the industry take much needed steps towards achieving net-zero carbon by 2050 �

Istanbul Airport © Jim Stephenson 2019