Heathrow announces major revamp and third runway plans — but will it happen?

London's Heathrow Airport (LHR) will submit a proposal for a third runway to the U.K. government this summer. The airport aims to have flights take off from said runway within the next decade.

The privately funded expansion will be part of a multibillion-pound investment that will also revamp LHR's terminals 2 and 5 to increase capacity.

These new investments will build on the 2.3 billion pound investment Heathrow announced in December 2024 to improve service, passenger experience and sustainability over the next two years.

A long-awaited expansion

Heathrow is the busiest airport in Europe and the fourth busiest globally. The London hub's two runways handle 83.9 million passengers annually, with a government-imposed cap of 480,000 flights annually. The airport hopes that a third runway could increase that limit to 720,000 flights, opening the door for new routes, more connections and reduced delays.

"We will submit our plans for a third runway to Government this summer," Heathrow CEO Thomas Woldbye said in a speech at British Steel's Scunthorpe plant.

"Ahead of then, as part of a phased expansion programme and supported by the Government's clear backing, I am today confirming multi-billion-pound investment plans, 100% privately funded, to upgrade our terminal buildings, enhance passenger experience, and improve resilience and sustainability," he continued.

Woldbye's ambitious plan aims to make the third runway operational before the end of the next U.K. parliamentary term; this means we may see a third runway at Heathrow before 2035.

However, given the history of the airport's much-debated third runway, any plans will likely face legal challenges and regulatory hurdles.

What would Heathrow's third runway plans mean for travelers?

Heathrow's expansion could bring significant improvements for passengers. The most obvious change would be that more flights would be able to take off and land at the airport. This increased capacity would also likely mean an increase in the number of direct flights from North America, along with new routes to the hub.

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Considering that Heathrow's runways are currently operating at full capacity, a third runway would also spread the load and hopefully improve efficiency, delay and congestion concerns at the airport.

Meanwhile, planned upgrades to the airport's terminals 2 and 5 (both of which are used extensively for transatlantic travel) would be a welcomed improvement to passenger flow and security operations. It may even see the addition of improved lounge experiences and offerings.

Related: The best lounges at London Heathrow — and how to get inside

What challenges does the expansion face?

Despite recent U.K. government support, Heathrow's expansion remains highly controversial. Environmental groups and local communities oppose the project, arguing that a third runway will increase carbon emissions and make it harder for the U.K. to meet its climate targets. Legal challenges and judicial reviews could further delay progress.

Referencing these challenges, Woldbye said that "this project can only go ahead if we meet the rules on noise, air quality and carbon that the Government sets out in the Airports National Policy Statement — it's as simple as that. "

In his speech, Woldbye drew attention to Heathrow's commitments to sustainable aviation fuel and the reduction of its noise footprint.

As part of the announced investment plans, Heathrow bosses will aim to introduce new infrastructure to improve its environmental credentials — including more sustainable sources of power to support its sustainability targets.

"I want to assure you that we are committed to listening and working with our local communities to provide them with the certainty they deserve, ending years of doubt," Woldbye added.

When could the third runway start operations?

The timeline for Heathrow's third runway remains uncertain. Even if the planning approval process moves quickly, the legal challenges, regulatory processes and construction could still take well over a decade.

U.K. Chancellor Rachel Reeves has previously said that she wants "spades in the ground" by 2029 and flights operating by 2035. But, it would be wise to err on the side of caution when it comes to meeting any early deadline.

For now, Heathrow's terminal expansions and infrastructure upgrades will begin later this year, promising short-term benefits for travelers. The third runway project, while now seemingly a serious long-term goal, could still be quite a ways off.

Bottom line

If Heathrow's expansion goes ahead, travelers could see more direct flights, reduced congestion and a better overall experience at the U.K.'s largest airport. However, with regulatory and environmental battles ahead, the third runway may still be a long time coming.