BAA has unveiled plans for the new £1bn Terminal Two building at London's Heathrow Airport, which has been designed to emit 40 per cent less carbon than the existing second terminal facility.

The new development will cater for around 20 million passengers each year and forms part of BAA's wider £4.8bn investment in improving services and facilities at one of the world's busiest airports. Plans for Terminal Two, which will become the new home for Star Alliance airlines, include 11,300sq m (121,632sq ft) of floor space to accommodate self-service check-in facilities, fast-bag drops, traditional check-in desks and 15 security search lanes.

Initial designs drawn up by international architects Foster + Partners and developed by HETCo - a joint venture comprising Ferrovial Agroman and Laing O'Rourke - also incorporate a two-level departure lounge with large windows to reduce the need for artificial lighting and solar panels to further reduce energy dependency. Construction work will be carried out in two phases, with the first set to include the creation of a 185,000sq m (2 million sq ft) terminal building on the site of the existing Terminal 2 and Queen's Buildings, which will be demolished later this year.

The first phase is expected to be completed in 2013 ahead of the second stage of work, which will see the new Terminal Two facility extended into the existing Terminal One building, as well as the construction of a second satellite building to increase Terminal Two's capacity to 30 million passengers a year by 2019. Mike Brown, Heathrow Airport's chief operating officer, said: "These exciting plans will be a reality for millions of Heathrow's passengers, making every passenger journey a better one and underlining Heathrow's pre-eminent position at the heart of international travel and the global economy.

"The new Terminal Two is part of a major programme of work already underway. Passengers travelling through Heathrow will be using new and extensively refurbished facilities which provide us with an excellent platform from which we can provide a better service to our customers than ever before." The unveiling of the plans comes as Heathrow Airport reported a stabilisation in passenger numbers during July, despite an overall fall in the number of people travelling through BAA's seven UK airports compared with the same period last year.

Edinburgh Airport, which may have to be sold by BAA following a ruling by the Competition Commission, reported its fourth successive month of growth with a 5.6 per cent rise in passenger numbers.