Draft expansion plans which could see a third runway and a sixth terminal at Heathrow Airport have been published.
Proposals include a boundary for a potential third runway
About £7bn would be spent over the next decade, building Terminal Five and upgrading the west London airport.
Proposals earmark land for growth, including a boundary for another runway and terminal, which would require the demolition of about 700 homes.
BAA Heathrow says the plans are not set in stone, but opponents say it will increase noise and pollution.
A fifth terminal at Heathrow, with an overall budget of £4.2bn, is due to open in 2008.
But BAA Heathrow says it still needs to modernise to meet growing demand for flights in the South East and believes there is a "strong economic case" for a sixth terminal.
Expansion plans could see the annual number of passengers rise from 67m to 116m in 2030.
The government has said a new runway and another terminal could be built at the airport - but first it has to meet environmental targets.
Mick Temple, BAA Heathrow managing director, said Heathrow could not afford to stand still but said they had to expand it in a way "which is both socially and environmentally responsible".
"This draft is for consultation only and should not be considered as final," he added.
But he said the whole project could be shelved if they could not meet environmental targets.
"We will not be able to build this additional runway without addressing these air quality issues," he said.
If approved, a third runway would not be built until 2015 at the earliest, he said.
Two schemes to help residents affected by proposals either move or try to maintain the value of their houses was also announced.
But John Stewart, chairman of local pressure group Hacan, said a third runway would "bring more noise, more pollution, and people will lose their homes".
"It's also not necessary for the economy. Unemployment is at an all-time low in west London.
He added: "No-one's going to want to buy a home here if they think the third runway's coming."
The draft plan will be put out for consultation until the end of October.