Heathrow has submitted a £49bn privately financed proposal to deliver a third runway and major terminal redevelopment within a decade.
The plan would increase passenger capacity by more than 75 per cent and could create significant opportunities for UK construction firms.
The scheme centres on the delivery of a 3,500-metre third runway located to the north-west of the existing site, supported by a new “T5X” terminal complex west of Terminal 5.
This would include a new processing terminal and a satellite terminal to the north, “T5XN”, connected via an underground transit system. Heathrow said this would enable at least 276,000 additional flights annually, increasing total air traffic movements from 480,000 to 756,000.
Terminal upgrades form a major part of the scheme.
Heathrow plans to close its oldest facility, Terminal 3, and extend Terminal 2 as part of a phased redevelopment of the Central Terminal Area.
This would be delivered alongside the wider modernisation of the airport estate, including expansion of airport parking, improved public transport links and enhanced cargo facilities. Cargo handling capacity would increase by 50 per cent, with new freight warehouses proposed to the south of the airport.
The expansion also includes a significant highways engineering package.
The runway would cross the M25 between junctions 14 and 15, which Heathrow proposes to reroute 130 metres westwards and lower into a new tunnel.
Construction of the new route would take place offline before traffic is switched over, to minimise disruption.
Heathrow chief executive Thomas Woldbye said the proposal was “shovel ready” and could start driving investment into the UK supply chain this year if government gives the green light.
He said the plan builds on years of consultation and technical work, and remains the only viable way to meet the government’s stated aim of granting development consent by 2029.
Heathrow has committed to delivering the entire scheme through private investment, with no taxpayer funding.
Of the £49bn total, £21bn is allocated to the third runway and £27bn to new and upgraded terminals and associated infrastructure.
Transport links
The scheme also includes a major rail and roads component.
A new Southern Road Tunnel is proposed to link the southern perimeter to the Central Terminal Area.
This will include dedicated bus lanes, unlocking previously unviable public transport routes. Heathrow is also exploring a combined rail scheme incorporating both the Western Rail Link and the long-delayed Southern Rail Access.
The airport has pledged to deliver all works in compliance with net zero targets by 2050, using sustainable aviation fuel, airspace efficiencies, and modal shift to public transport.
Biodiversity net gain, noise mitigation measures, and school and housing insulation schemes are also included.
The submission follows government backing for Heathrow expansion, confirmed by chancellor Rachel Reeves in January 2025.
Heathrow said that it aims to submit a full planning application in 2028, with construction starting shortly after. The first flights from the new runway could take off by the mid-2030s.
Yesterday, Construction News reported that the Arora Group had submitted a rival expansion proposal for Heathrow Airport, promising a lower-cost and less disruptive alternative.