Flights of fancy? Weighing up Britain’s airport options

The Howard Davies commission has left the door open for Boris island alongside possible expansion of Gatwick or Heathrow – but what are the pros and cons of each?

Isle of Grain: new hub airport in Thames estuary

The plan
Build a new four-runway airport in the Thames estuary. Cost: up to £112bn by 2030.

Benefits

• A new aviation hub – “Boris island” would secure London’s status as a crucial hub for connecting world flights
• Less noise – opting for a new hub on the Thames would mean closing Heathrow and stopping its much-maligned flights over large parts of London. The noise from flights using the new Thames hub would affect far fewer people
• Local regeneration – a new hub could reinvigorate deprived surrounding areas and bring in 100,000 new jobs in the airport alone in the 2030s
• Ideal for London expansion – the Thames hub would support the massive expected growth of east London, in plans set out by Boris Johnson
• Potential for even more expansion – the Isle of Grain scheme would offer much more potential for future growth than Heathrow
• More space for new housing – the space currently occupied by Heathrow could be re-used to bolster the UK’s ailing housing stocks

Drawbacks

• Huge cost – potentially more than five times the cost of the other options
• Demolition – about 1,600 homes would be lost and an entire community would need to be relocated if the hub went ahead
• Loss of jobs – Heathrow is linked to 8-10 per cent of employment in the surrounding boroughs
• Making life tough for business – closing Heathrow would make the surrounding area less attractive to new businesses and make life tougher for those already there
• Flood risk – the chances of severe flooding at the new hub would be “of a different order of magnitude” compared to the risk at Gatwick or Heathrow, according to the Davies commission
• Lacking transport – located 33 miles from central London, the hub would require a whole new network of transport links to become viable
• Impact on nature – protected species would be threatened by the Thames hub

Heathrow: new runway to north west, or extend northern runway

The plan
Build a third runway 3,500m long to the north west of the existing runways. Or extend the existing northern runway to the west to at least 6,000m long, to enable planes to take off from and land on the same strip. Cost: up to £18bn until 2030.

Benefits

• Growth of the UK’s “hub” status – Heathrow expansion would build on its existing position as a crucial hub for connecting world flights
• London proximity – Heathrow has some of the best London connections among the options being considered, and planned rail schemes will only improve its accessibility
• Neutral noise impact – although both Heathrow expansion options would lead to more flights, their flight paths would be changed, meaning that overall noise would not worsen

Drawbacks

• Demolition – a new runway to the north west would require knocking down 1,500 houses including the loss of an entire village, Harmondsworth. But extension of the northern runway would mean demolition of only 270 homes, the fewest of all the options

Gatwick: new runway to south

The plan

Build a second runway 3,000m long to the south of the existing runway. Cost: up to £13bn until 2030.

Benefits

• Flight growth – more point-to-point flights could be offered, and Gatwick could become a connecting hub in its own right
• Minimal disruption – about 200 homes would need to be demolished to make way for a second runway and there would be no loss of greenbelt land

Drawbacks

• Noise – will increase, but Gatwick would remain quiet compared to other airports
• Pressure on transport – existing links would be put under more strain, although improvements are already planned