Poland's new airport, the Centralny Port Komunikacyjny (CPK), is set to open in 2027.

Various architectural firms are currently competing to take charge of the official design, which will ultimately be decided on by 2020.

From translucent roofs and leafy surroundings to Jewel Changi-inspired looks and an "Airport City" bigger than Manhattan, here are five design proposals for the CPK.

Visit Business Insider's homepage for more stories.

The Centralny Port Komunikacyjny (CPK), Poland's new airport, is set to open in 2027.

Located between Warsaw and Łódź, the CPK will initially serve roughly 45 million passengers per year, with the view to eventually serve up to 100 million passengers, according to Polish government documents.

This would place the new transport hub within some of the busiest airports in the world – Hartsfield-Jackson Atlanta International Airport was ranked as the biggest airport in the world in 2018, serving 107,394,029 passengers.

Though LOT Polish Airlines' new hub will be inspired by some of the world's best airports, including Singapore's Jewel Changi, secretary of state at the Polish Ministry of Infrastructure Mikołaj Wild also told Business Insider in an interview that the design will ultimately be decided by an international competition between architectural firms.

So far, the company responsible for the CPK's construction has received six architectural concept ideas for the new airport, which are to be an inspiration during the preparation of the master plan and further design works.

Read more: A blog was fined $29,000 for saying a Chinese building designed by Zaha Hadid had 'bad feng shui'

"We have invited a number of prominent architects, armed with a wealth of knowledge, professional experience, and creativity, to come and work with us and we're glad we did," said Dariusz Sawicki, the managing director involved with airport planning for the CPK.

"The firms' bold concepts have somewhat clashed with the investors' expectations, and it's turned out to be deeply inspiring — in some cases, it's opened our eyes to unusual design solutions we hadn't previously considered."

Among those who entered the five design concepts are Chapman Taylor, Foster+Partners, Grimshaw, Zaha Hadid Architects, and Benoy.

Chapman Taylor wants to design CPK in the shape of a key and the letter "X"

British studio Foster+Partners has suggested that the CPK should feature two terminals — one in the shape of a "key" and the other in the shape of the letter "X".

The terminal itself would have a translucent structure. Foster + Partners / Press Materials

The firm also proposed that an airport shuttle system would connect the two terminals.

The terminal itself would have a translucent structure, allowing sunlight to reach the inside of the building.

In addition, it would also incorporate a wooden finish and provide space to plant trees.

Grimshaw's vision features an urban marketplace

Grimshaw architects put forward the idea of an airport featuring a more of a "hub" feel.

The concept by Grimshaw. Press Materials

Their vision includes a reasonably proportioned airport that veers away from the excessive size of some more recently built connecting airports, with a view to reducing the time transfers take, and to shorten the walking distance for travelers.

Read more: Beijing's new Daxing Airport will be the biggest in the world when it opens later this year. Here's what it looks like inside the impressive $12 billion construction project.

Among other factors, the use of natural light, the reduction of the airport's length, and the "stacking" of the terminals were at the core of Grimshaw's design.

Though the design idea behind the terminal was focused on minimizing the stress associated with transfers, the architects also put forward the idea of incorporating a space for performances and events somewhere in the airport.

Chapman Taylor envisioned the CPK beneath a transparent dome

The aspect that stands out most in Chapman Taylor's design proposal is the transparent dome.

In this concept, the main part of the terminal located between the two runways would be covered with a glass construction, to symbolize "infinite unity".

Chapman Taylor's design proposal includes a transparent dome. Press Materials

Consisting of six levels, the terminal would be comprised of railway platforms, a stopover area for train passengers, arrivals, departures, business lounges, and a mall area with shops and restaurants.

Read more: The world's best airport just unveiled a $1.25 billion glass dome mall with a rainforest, waterfalls, and bejeweled clouds

Each of them will be inspired by a different element of the country's landscape — the coast, the lakes, the lowlands, the highlands, the valleys, and the mountains.

The designers admitted they'd been somewhat inspired by the Jewel Changi Airport in Singapore, which incorporated a lot of natural greenery into its interior.

In each of Zaha Hadid Architects' three concepts of the CPK, the focus is on incorporating rail transport into the airport.

Zaha Hadid Architects proposed three similar visions for the new Polish airport.

As well as carefully thought out interior lighting, all three concepts would also include lush greenery.

The first concept features a railway line directly below the airport, theoretically allowing passengers on the upper floors to observe arriving and departing trains.

Zaha Hadid Architects' first concept. Press Materials

The firm's second vision features a station that would, instead, sit above platforms, which would connect other parts of the airport.

Zaha Hadid Architects' second concept. Press Materials

The third concept entails trains arriving directly at separate points across the terminals, which will be located on platforms at different heights.

Zaha Hadid Architects' third concept. Press Materials

The CPK would be bigger than Manhattan, based on Benoy's concept

Architects from Benoy explained that once built, the CPK would cover an area larger than the entirety of Manhattan.

Essentially, the firm is not only putting forward a concept for the development of an airport; it's also proposing plans that will transform the surrounding area.

These outlying areas would eventually become various parts of the "Airport City" — from hotels and conference rooms to logistics centers and offices.

Benoy said that, once built, their vision of the CPK would cover an area larger than the entirety of Manhattan. Benoy / Press Materials

Benoy has suggested that, regarding the interior of the terminal, the boundaries between each zone should be as smooth, seamless, and invisible as possible.

The airport's official master plan, which will define its direction for its first 25 years, is to be drawn up and finalized by 2020.

KPF studio's architectural concept for the CPK. CPK

The architects who came up with the idea for the triangle-shaped terminal have also worked on airports in Abu Dhabi, Amsterdam, and Seoul.

The shape is meant to ensure that the distances between the furthest points of the airport won't be too far, a common gripe of airport travellers these days.

KPF studio's architectural concept for the CPK. CPK

"The triangular shape of the terminal is optimal from an architectural point of view and offers a lot of benefits. It offers convenient movement and reduces the time it takes for flight transfers," said architect Jens Hardvendel from KPF.

"The triangle is also a really nice shape, reminiscent of clasped hands — it's associated with solidarity, which will resonate a lot with many Polish people."

As well as the roof of the triangular hall being transparent, creating as much natural light as possible, there will also be skylights.