Karl Lyndon, global aviation sector leader at integrated engineering consultancy, BuroHappold, explores the growing focus on greening airport terminal buildings.
The aviation sector has been attracting a lot of attention recently – and not all of it for the right reasons.
The new trend of ‘flight shaming’ in a bid to discourage air travel and reduce carbon emissions has attracted c-suite attention and an acknowledgement that more must be done to demonstrate the sector’s wider environmental credentials. The growing sustainability and energy efficiency of airport terminal buildings is a case in point.
Of course, the greening of airport terminals is not a particularly new concept, but our understanding, as a sector, of how to respond has improved significantly. Now, there is a growing focus on tackling the ‘big wins’ – energy, waste and carbon in both new and existing buildings.
Far from being a ring-fenced area of CSR policy, sustainable design is increasingly recognised as a means to deliver not just environmental value but social and economic value too – with measurable improvements in the performance and quality of airport facilities.
To effectively respond, the focus must be on outcome-driven design and on creating airport terminal buildings that work both now, and in the future.
The application of data-driven technology is key in mapping all aspects of an airport – from footfall to cargo and logistics, ensuring sustainable planning and design also translates to maximum financial returns and an unrivalled airport user experience. So where should our attentions lie?
Greening terminal buildings
When it comes to ‘going green’, much of the focus has rested on reducing carbon footprints. However, the legacy approach of the voluntary carbon off-setting market means that progress and gains can be difficult to evidence.
There are, of course, ways to apply a more bespoke, ‘on-site’ approach to carbon reduction – using the ‘campus’ nature of airport sites and buildings, for example, to invest in clean energy such as photovoltaic panels, or low carbon on-site biomass.
While a valid and worthwhile approach, this requires significant investment up-front and presents logistical challenges.
Reducing energy use presents a more immediate and straight-forward solution. It also offers very real economic value.
At BuroHappold, we have conducted a detailed analysis of energy use in fifteen airports of varying ages. The research shows that energy use within a typical European airport terminal building can broadly be carved up as follows – a quarter on baggage handling, slightly less than a quarter on lighting, a quarter on fans and pumps, and a quarter on heating and cooling.
Tackling these areas requires full collaboration between the airlines, airport operators, architects and design teams and a holistic approach that should always begin with energy analysis. The approach must be one of co-creation and co-design, pooling existing operator knowledge with specific design expertise.
The recently opened Beijing Daxing International Airport, with its 700,000sqm terminal, is a prime example of how this sort of collaboration can deliver the combined benefits of energy efficiency, a strong user focus and the flexibility to sustain future growth.
Environmental drivers played a key role with numerous passive elements incorporated into the design, including shading strategies, high performance glazing, and carefully placed roof lights that optimise the energy performance of the terminal while benefiting the wayfinding.
These solutions predicted a 50% reduction in overall energy consumption and CO2 emissions.
The growth of the smart airport
Daxing is a timely reminder that, in tackling energy use and management, the changing nature and design of airport buildings presents a real challenge.
Terminal buildings are increasingly big, flat and wide in their design, in order to cope with growing passenger numbers, peaky flight schedules and a requirement for more space to accommodate taxiing and parked planes. Larger spaces mean that there is a growing need for smart airports that can be effectively zoned and managed.
The size of airport zones typically leads to the use of standard HVAC (heating, ventilation and air conditioning) controls, set to conservative values. Increasingly this standardised approach is being challenged to direct passengers to one part of the building or zone, thereby reducing energy use in the other areas.
Baggage reclaim is a good example. Traditionally, these expansive areas will be ‘100% live’ during operational hours, but will have only a few reclaim belts in operation serving arriving passengers.
By managing logistics and driving passengers to one section of the baggage reclaim, airport operators can set back the building systems and lighting into ‘sleep mode’.
The size of airport terminal buildings also needs consideration as part of the energy efficiency mix. Often airports are oversized and outdated compared to their required functionality and modernising and right-sizing can save millions of dollars in energy use.
Pittsburgh International Airport, in the US, is a case in point. Formerly a US Airways mega-connecting hub, the airport has transitioned to a growing origin-and-destination facility focused on improving the passenger experience, reducing long-term costs and advancing the region.
As part of its Terminal Modernisation Program, a new landside terminal to be constructed adjacent to the existing airside terminal will consolidate operations under one roof, reduce the number of unnecessary gates and conveyances, repurpose existing spaces and eliminate reliance on the energy-intensive Automated People Mover.
Working together with airport staff and the terminal design team, our focus has been on ensuring that there is clear separation between the old and new infrastructure in order to avoid prohibitive costs associated with system upgrades and to advance more sustainable building design.
We are co-creating the strategy for the Building Management System (BMS) that will integrate with legacy systems to provide the best long-term solution, and our extensive Building Information Modelling (BIM) capabilities have enabled us to work with the Gensler+HDR-led design team to co-ordinate and develop the airport terminal concepts.
A Single Analysis Model has been used to develop a ‘whole building’ approach to energy modelling, evaluating energy conservation measures and their impact on operational costs.
Right-sizing in this way is not always an option, however, and, in some instances, growing travel means increasing the size of the terminal building. This was the case at Oslo Gardermoen airport in Norway where the expansion included a new 300m long pier and 115,000sqm terminal extension.
Doubling the size of the existing building, this project created one of the greenest airport terminals in the world.
One of the key goals was to cut energy demand by 50% – no small task given that the old terminal was already one of the world’s most energy efficient! This also needed to go hand in hand with enhancing passenger comfort and well-being.
We created a dynamic building envelope that could respond to changing external conditions with minimal energy use, undertaking careful modelling and analysis of the building’s design and orientation to develop a curved extension complete with panoramic window.
This works in tandem with the skylight that runs along the length of the pier to promote passive solar heat gain and temperature control, while enhancing passenger experience with extensive views and easy wayfinding.
We also paid careful attention to the materials used throughout the building. The new pier is clad in regionally-sourced timber, while the extension itself is made from recycled steel concrete mixed with volcanic ash. This is said to be more environmentally friendly than standard cement-based concrete due to the lower temperatures required to mix it and the expectation of a longer lifespan.
This really was a landmark project for the aviation sector. The holistic approach to sustainability allowed the design team to realise the first ever BREEAM Excellent rated terminal and establish a new benchmark for sustainable aviation.
Letting the light in
While the normal flat, deep design of airport buildings casts light around the periphery, this only usually covers around 10% of the overall floor area. Further towards the centre of a terminal building, a significant amount of energy is often required to sufficiently light the space.
Design and engineering teams are therefore pushing the boundaries of design to let light in. At Changi Airport in Singapore, for the Jewel project, we used unique glass designs to maximise natural light.
From the outset, the aim was to make the new building breathtaking, but this had practical implications on energy management.
Nearly 10,000 unique, triangular glass panels are connected by 14,000 steel elements and more than 5,000 nodes at Jewel Changi. At 210 x 156m, it is the world’s largest gridshell enclosed building. It also features the world’s tallest indoor waterfall.
The expansive glass roof and waterfall oculus, open to the elements, has a knock-on impact on heating and ventilation control, and BIM has been key to ensuring all elements of the project can work in unity.
While the glass has been designed to maximise the light inside the building, glass fritting has been used to control solar heat gain to create a comfortable environment for both plants and people, while the interior climate is managed by a series of vents hidden amongst the plants of the valley garden.
A bespoke approach
Of course, each airport terminal – whether new or existing, requires individual consideration of varying factors dependent on geography, size of building, and surrounding climate.
The focus on ‘going green’ is a common one however, and as we move forward, it will present us all with new and changing challenges.
Wide-scale global warming and climate change will require increased resilience in our terminal buildings, and we can expect a move towards some self-sufficiency of electrical and water supply.
Taking steps to change now will support long-term environmental, social and economic value. We all have a responsibility, and an opportunity, to act.