We can’t all be Changi: Here's what it takes to build an airport

Wilbur and Orville Wright took the world’s first flight in 1903, and within 20 years, the world’s first airports were up and running.

Though the very first airport is debated — it could be any number of airfields across the U.S. where the Wright brothers and the U.S. military flew — some of the earliest commercial airports include Hamburg Airport (HAM), Amsterdam Airport Schiphol (AMS), Minneapolis–St. Paul International Airport (MSP) and Sydney Airport (SYD), all of which opened between 1911 and 1920.

While those airports were, more or less, waiting rooms and grassy fields, they’ve since turned into modern marvels, not only in terms of feats of engineering but also as entertainment and retail centers (case in point: Singapore Changi and its new Jewel complex). But they’re also essential to contemporary society, functioning as the gateways to the world. So, how do you even build an airport? It’s much more complex than it might seem.

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Identifying the problem

There are two kinds of airports in this world from an airport planner’s point of view: an existing terminal that needs to be renovated and what’s called a greenfield — a clean slate for a new build. In either case, the project has a simple goal: to improve functionality and the passenger experience. (It’s exceedingly rare for an entirely new airport to spring up where there was never a facility to begin with. New builds usually only occur because an older facility can no longer meet demand.)

“Typically what happens is a capacity constraint or a deficiency in passenger experience has been identified, at which point an airport will develop a project brief that looks to identify the problem and determine what is causing that issue,” says Jackie Coburn, an airport planner and architect at consultancy Arup.

“Sometimes, an airport will provide a great deal of definition, or they can be pretty loose. You're being commissioned to solve the problem, but you might have to ... define what the actual issue is first.”

When it comes to airports, it’s typically the owners who are calling the shots. And, in most cases, particularly abroad, that’s the government, whether at a federal or a municipal level. In the United States, however, there’s a growing number of airports that operate under a public-private partnership.

Take LaGuardia’s Terminal B, for example, which is a project between the Port Authority of New York and New Jersey, (the government entity), and the LaGuardia Gateway Partners, a consortium of private entities led by developer Skanska.

To throw a wrench in the whole thing, airlines can also get involved, signing long leases on terminal space and investing heavily in their development, particularly in the U.S.

For LaGuardia’s Terminals C and D, Delta is investing some $3.4 billion into their renovation and expansion over the course of a decade-long construction project, with the Port Authority investing just $600 million. Delta’s current lease was signed in 2017 and will last 33 years. Across the borough, at New York-JFK, JetBlue is currently signed for a 28-year lease at Terminal 5. The airline worked closely with architecture firm Rockwell Group and Gensler on the very branded aesthetic of the space, with Arup working on the master plan.

“In all airport projects, you are interfacing with a large number of stakeholders — the owner, airlines, concessionaires, government authorities like the TSA or Customs and Border Protection,” said Coburn. “The one difference when [an] airline actually designs and builds the project, is that your day-to-day involvement with the airline is more than if you are engaged by the airport itself.”

Having all these entities at the helm is what makes determining an airport’s problem — not to mention the solution to that problem — quite challenging. That's why owners turn to architecture and engineering firms and consultancies like Arup to work on the project. “We start with capacity-demand analysis, then do master planning, then design and construction,” Coburn said.

Related: Formulaic or flamboyant? How architects work to make airports feel local

Crunching the numbers

Regardless of whether or not a project is a renovation or new build, all airports have the same major functions, meaning there’s a relatively straightforward checklist of what needs to be included in the master plan.

In terms of passenger departures, airports need space for check in and bag drop, security, airside concessions (at the very minimum, a newsstand with food and beverage, though most airports are choosing to include expansive retail and dining options), bathrooms, waiting areas with seating and outlets, and gates. Then, of course, there are special features like lounges, pet-relief areas or even an airside hotel.

On the arrivals side, there’s immigration and customs for international airports, as well as baggage claims.

In order to determine how much space is needed for each of those components, airport planners input data from the airport project and use mathematical formulas based on different data points. It all starts with the airlines, who provide daily flight schedules to the planners; there's plenty of information to work with.

“You try to identify what’s called the planning day, which is one of the busiest days of the year,” said Coburn. The planning day should represent the 95th percentile of the calendar year, meaning that 95% of the time, you’ll have fewer crowds than that planning day. “The top 5% is your unusual days, like the time around Thanksgiving or Christmas when you’ll be experiencing some congestion,” she added.

Determining your planning day simply comes down to math. “The schedule shows when flights arrive and depart, what aircraft they are, where they’ve come from, where they’re going,” said Derek Moore, an aviation practice leader at SOM. “By knowing [the] times, aircraft, origin and destination, we then apply a whole series of planning parameters to calculate the number of passengers, the number of gates, the size of the bag system. We can derive from that schedule using straightforward spreadsheet mathematics.”

Coming up with the master plan

Once all those numbers are crunched, they can be input into simulation software, which allows planners to start laying out the actual floor plan of the airport.

“Airports are large sources of data. Airlines and airports have statistics on how long it takes to check in your bag, how long you spend at a kiosk or how quickly you go through a security plan,” said Coburn. “We apply that data to the fight schedule, and we can determine exactly how much facility we need to deliver a target level of service.”

By tweaking the parameters, from the number of check-in desks and bathrooms to the distances between the gates, airport planners "can figure out how long of a wait time [and] how long of a queue is acceptable. Everybody wants to get as close to free flow as possible, but you need to be realistic economically.”

The schedule data and historical data also help determine the number of concessions — that is, food, beverage and retail outlets — placed in each terminal.

“The number [is] driven by how many people are being processed through the airport and how long they’re expected to be in the terminal,” Coburn explained. “Hub airports, for instance, often have passengers who move really quickly, but some may have long connections, and they may dwell in the airport for quite some time.”

While concessions are partially a practical need to keep passengers happy, they’re also a major revenue stream for airport owners, so airport planners do take that into consideration.

And finally, but most importantly, airports have to follow laws surrounding security and borders, which factor greatly into a layout. There are numerous sectors inside an airport, starting with pre-security, which is known as landside, where the check-in desks and baggage drops are. Then there’s post-security, known as airside, where the gates are. Within both sides of an airport there are further subdivisions, like international and domestic, as well as departures and arrivals. “You very quickly start to work in sections within a plan,” said Moore.

Passengers arriving from foreign countries (or outside of open-border zones like Schengen) need to be segregated from all other passengers until they clear immigration and customs. “On departure, it’s a little less complicated. You can generally mix most of the sectors,” said Coburn.

And there are exceptions. "A number of airports outside of the U.S. offer Preclearance, like Toronto and other major airports in Canada, Dublin, Abu Dhabi [and] the Caribbean. It means that you are processed and cleared into the U.S. before you’ve left the country that you’re in, and therefore you need to be contained in a separate zone from other international passengers.”

Some countries around the world have stricter regulations that require even further segregation. “In India, not only must you separate international arriving and departing [passengers]," said Moore, but even domestic arriving and departing traffic must be separated.

Maximizing efficiency

In a perfect world, airports would be designed so you'd hardly ever have to wait in line anywhere, but there are two major blocks to that scenario: space and money. As for the layout of an airport, planners are restricted to specific square footage, determined by either a preexisting terminal destined for a renovation or a greenfield, whose limits are dictated by its plot of land. And, of course, budget limits exactly what can be built or renovated.

In both renovations and new builds, one of the primary ways to maximize both space and money is the implementation of swing spaces, or airport facilities that can switch between sectors, with the flow of people controlled by a series of glass doors or moveable walls.

For example, airports can use certain spaces for domestic flights during the day, then switch over to international flights during the evening, after a thorough security sweep that clears the area. “That way, you’re not building twice as much building as you need,” said Moore. “The building is ultimately responding to the airlines’ schedules.”

Another method to use space efficiently is to use verticality. “Some terminals are designed with duplicate facilities stacked atop one another so that a single gate can be served by different sectors,” said Coburn.

And as mentioned earlier, retail is an increasingly important revenue stream for terminal operators, meaning that travelers aren't supposed to move through an airport too quickly

Behind the scenes

Of course, the passenger-facing side of the airport is just one part of the facilities.There’s also the underbelly, like the baggage handling systems, not to mention the taxiways, runways and hangars for airport planners to consider. “The complexity of the back-of-house spaces can be as complicated as the front-of-house ones,” said Coburn. “Baggage systems are specifically quite complicated to fit into the geometry and spatial constraints of the building.

But, as with the passenger spaces, the behind-the-scenes side is heavily driven by the airlines’ schedules and functions.

“We test the building layout against a whole range of aircraft parking and maneuvering plans: how they get to the gates, move from the gates, get out to the runway,” said Moore. “It’s basically the orchestration of multiple movement systems, many of which are vehicles, some of which are equipment like baggage.

Related: From LAX to New York LaGuardia: Black architects make their mark on airports

The neverending story 

What’s perhaps most fascinating about building airports is that it’s a never-ending process. By the time an airport is planned and built — a process than can take a decade or more — the demands for the airport will likely have changed since the original project’s conception.

“There is a continuing cycle of planning design in airports. Part of the reason for that is aviation growth has been pretty consistent since the commercialization of air travel in the 1950s,” said Coburn. “And because they're such expensive infrastructure projects, it's very difficult to develop enough capacity in advance of demand, since it's so long before you would get your return on investment.”

It’s also difficult to predict what the future will hold in terms of technology, adding to the difficulty of designing an investment-heavy space that should last quite some time. For instance, intense security screening for both passengers and baggage was essentially nonexistent in the world prior to Sept. 11 world. So, after 2001, 40-year-old airports suddenly had to be retrofitted to fit new security equipment.

“By the time you develop an airport and bring it into operations, you’re already starting to work on the next project for it,” said Coburn.

So, will airports ever be able to break the proverbial wheel? Truthfully, it’s not likely, given that in just over 100 years, we’ve gone from the invention of the airplane to flying more than 4 billion people around the planet each year. As is the case for any piece of infrastructure, the demands for airports will constantly be in flux, meaning we might have to put up with renovations for the foreseeable future.