The CAA has written to Heathrow chief executive John Holland-Kaye setting out its expectations for the efficient delivery of a third runway.
The aviation regulator now has a role to play in determining how much Heathrow can charge airlines, and ultimately consumers, for the building and financing of the project.
The authority has emphasised to Heathrow the importance of the airport making it clear how it will deliver on its recent promises not to increase prices as the runway development progresses.
The CAA expects to see “effective engagement” between the airport and its airline customers to drive value for money and efficiency.
The regulator has also told the airport to set out clear plans for engaging with local communities and addressing their legitimate concerns around issues such as compensation, operational procedures and participation in the airspace change process.
CAA chief executive Andrew Haines said: “The need for additional aviation capacity is clear and we welcome the government’s announcement.
“We now expect Heathrow to set out how it will meet its promise not to increase prices and deliver a cost efficient programme in conjunction with its airline customers.
“We also expect the airport to ensure the legitimate concerns of communities near the airport are properly and fully considered and that a credible package of measures to manage those concerns is in place.”