Heathrow Airport has set out a four-phase plan for expansion by 2050.
So what is proposed for each stage?
Phase One – by 2026
The new runway is expected to be completed and opened by 2026.
New hotels and offices will start to be built, as well as a multi-storey car park at Terminal Four, and Colnbrook Railhead freight line will be realigned.
River corridors affected by the new runway and associated works will be diverted and new drainage and pollution control areas will be provided.
Harmondsworth Primary School, Heathrow Special Needs Centre and the Immigration Removal Centre will all be moved to new locations.
The A4 and A3044 will be diverted, as will a 12-lane section of the M25, which will be rerouted through a tunnel under the new runway.
There will be a so-called Green Loop of green space around the airport.
Phase Two – by 2030
Improvement works to Stanwell Moor Junction will be completed, a new southern road tunnel to the central terminal area will be built, and new road infrastructure in the south of the airport will be constructed.
Extensions to Terminal Five and Terminal Two will open.
Sites used for construction support will start to be returned to landscape.
Phase Three – by 2035
By 2035 the Southern Parkway, which will connect to the M25 and serve Terminal Five with direct shuttle services, will be completed.
Additional phases of the Terminal Five extension will have been built.
A parking area at the Northern Parkway site will replace some parking areas lost due to the expansion.
Phase Four – by 2050
Multi-storey car parking buildings will be completed to serve the Northern Parkway and a new aircraft hangar will replace Cathedral Hangar.
An improved road system between terminals will be completed to support “increased demands” and more accesses for aircraft to the runways will be added to improve airfield performance.