Heathrow today promised to spend £250 million improving noise insulation for those under the flight paths should it get a third runway.

The money is part of a £550m community compensation package, with the remainder set aside for buying homes to make way for the new landing strip.

The investment was announced this morning as bosses at the airport revealed their revised proposal for a new runway to the north-west of the existing two.

Among the measures announced for local residents and businesses are:

* moving the new runway further south so 200 fewer homes would have to be demolished and the Grade I-listed Great Barn at Harmondsworth and Grade II-listed St Mary's Church could be preserved at their current sites. The new location would also mean 12,000 fewer people falling within the 57leq noise contour than the 177,000 under the previous proposal

* compensation of 25 per cent above market value, plus moving costs, legal fees and stamp duty paid for anyone whose home would need to be demolished

* working with a panel of seven community representatives to develop a detailed compensation package worth £550m for public consultation this summer

* encouraging quieter aircraft, which coupled with other measures, Heathrow says means 30 per cent fewer people would be affected by significant aircraft noise than today

* steeper descents and planes landing 700m further along the runway, which, together with the runway being further west than under its 2002 proposals, Heathrow claims means planes would be 550ft higher over Heston and 570ft higher over Brentford

* maintaining runway alternation, ensuring periods of relief for those living and working under the flight paths

* providing new rail and bus options, including the possibility of a rail link between Heathrow and Feltham with six trains an hour by 2040

* considering the case for a congestion charge for passengers driving to the airport or being dropped off by car, to help reduce NO2 emissions around the airport to within EU limits

* ensuring the M25 remains open while tunnelling work takes place to the north-west of the existing airport, and widening motorway to provide 14 lanes between junctions 14 and 15

* protecting more than 100,000 existing local jobs and creating 50,000 new jobs around Heathrow, including 35,000 at the airport itself

* doubling the capacity of the airport's cargo area to support business in the area

Heathrow estimates the new runway and associated work would cost £16.8 billion, all but £1.2bn would come from private investment, and could be ready by 2025.

Speaking at the launch of the revised plans this morning, John Holland-Kaye, chief executive designate of Heathrow, said: "We know that opinion is divided locally about whether a third runway should go ahead or not, but everyone has an interest in making sure that if a third runway does happen it is developed in the best way possible.

"This is why we have gone to lengths to ensure that local residents' and businesses' views have been reflected in our submission. We would like to thank those who participated in the consultation process and have helped shape our plans for a third runway."

More than 13,000 people responded to Heathrow's consultation on its third runway proposals, with nearly 40 per cent saying the most important issue was noise. Jobs was only fourth on the list of priorities, behind aircraft safety and air pollution.

Although the new noise insulation package promised is far more generous than the £30m pot available at present, Heathrow has been criticised by Brentford & Isleworth MP Mary Macleod for dragging its feet when it comes to meeting existing guarantees to schools under the flightpath.

The MP is due to meet aviation minister Robert Goodwill and representatives from Hounslow Council today to discuss what an aide described as the 'slow progress' to date on noise insulation works.

The aide said there was a 'good deal of work to be done' for the airport to meet its obligation to retro-fit double glazing to doors and windows at schools under the flight paths and to provide mechanical ventilation.

She added that Hounslow Council had been pressing Heathrow to do additional noise insulation work but Heathrow had been 'reluctant' to carry it out.

Asked why, given it was not meeting existing obligations, residents should trust Heathrow when it cames to promises of future investment, Mr Holland-Kaye said: "We're working actively with Hounslow Council to complete our existing insulation programme. Around the airport there are a small number of schools waiting to get insulation.

"We do envisage this (improved noise insulation for schools) being part of the £250 million we are planning to spend."

As before, a new runway would increase capacity at Heathrow from the current cap of 480,000 flights a year to 740,000 - 40,000 more than at Paris and Frankfurt airports at present.

Heathrow is due to submit its revised third runway proposals tomorrow to the Airports Commission, which is considering the case for aviation expansion in the UK and is due to make a final decision next summer after the 2015 general elections.

Gatwick is also submitting more detailed plans for a second runway, while Heathrow Hub, which is independent of Heathrow, is publishing its plans to extend the northern runway at Heathrow to the west, allowing it to operate as two separate runways.

How the figures stack up in the fight for a new runway

Heathrow claims a third runway would provide a £100bn boost to the UK economy, £40bn less than Gatwick claims its second runway would bring, though Heathrow bosses said its estimate ranged from £40bn to £200bn, showing how inexact a science such forecasts are.

The £250m noise insulation package offered by Heathrow is nearly three times as generous as the £90m promised under its previous proposals back in 2002.

However, Gatwick today again upped the ante when it came to compensation for those living under its flight paths. It promised to provide £1,000 a year towards council tax as a sweetener for those worst affected by aircraft noise should it get a second runway.