Heathrow is to spend hundreds of millions of pounds in an attempt to buy off local opposition to a proposed third runway, with plans to use a massive new fund to compensate homeowners and insulate homes and public buildings against aircraft noise.

With the airport set to publish detailed plans on Tuesday for a new runway to the north-west of its current perimeter, it is prepared to pay premium prices for properties in its path as well as to offer unprecedented sums for sound insulation from a £550m fund.

Around 750 homes would be compulsorily purchased and demolished if the scheme goes ahead. Heathrow would offer an exceptional 25% over the unblighted value of the houses (averaging £250,000) along with legal fees and stamp duty incurred for the purchase of new homes.

Allowing for a potential 15% rise in house prices, Heathrow would expect to spend at least £250m on soundproofing homes and schools – compared with only £30m it has spent on insulating properties in the last 20 years.

The third runway at Heathrow is the bookmakers' favourite to be selected from three airport schemes shortlisted by the Airports Commission, led by Sir Howard Davies. An alternative Heathrow development proposed by the Heathrow Hub group, which owns options on land nearby, and a second Gatwick runway are still under consideration, along with the possible 11th-hour reinstatement of a new Thames estuary airport thought up by London mayor Boris Johnson.

A final recommendation will be made after the 2015 general election, although no party has pledged to implement Davies's findings.

Noise has long been a pivotal issue around Heathrow, with surrounding boroughs such as Hounslow resisting expansion. Many residents report being woken daily at 5am by the first arriving flight, while teachers in schools under the flightpaths say lessons are frequently rendered inaudible by incoming planes.

Heathrow is planning another public consultation in July to decide how the money should be divided up. The size of the fund could conceivably see grants for insulation in areas beyond the "noise contour" of what was traditionally considered persistent disturbance.

A source said: "We want people to work with us to decide how that should be implemented. There are choices to be made on whether we focus resources on high-noise areas or spread them thinner and further, whether it should be residential or community buildings. Do we insulate all schools to a gold standard, or would schools rather spend the money on better facilities?"

On Tuesday, Heathrow will publish a 400-page document setting out a revised plan for the third runway, slightly farther south than set out last year but still obliterating most of the village of Harmondsworth. The airport will also include a report from a public consultation underlining its belief that the alternative Heathrow Hub proposal – based on former Concorde pilot Jock Lowe's vision of elongating the two existing runways for landing and takeoff, would be even more fiercely resisted locally, as it would jeopardise periods of respite for residents under the flightpaths.

Colin Matthews, chief executive of Heathrow, said: "We are committed to treating those most affected by a third runway fairly. Since the previous runway plan was rejected in 2010 we have listened to ideas for how we could improve our proposals. We recognise that the expansion of Heathrow deserves an exceptional compensation scheme. That's why we're going further than statutory schemes or government guidance."

John Stewart, of Hacan (Heathrow Association for the Control of Aircraft Noise), who chaired the coalition of anti-third runway protests last time round, said Heathrow's move would mark "a whole new approach". He said: "We'd always welcome generous terms of compensation and mitigation, but this has all the desperation of trying to buy off the opposition. Whether this will actually get Heathrow the third runway they desperately desire is very much open to question. Their newfound generosity is a clear sign that they are still not confident that they can get a third runway approved, agreed and built."

But, he admitted: "Heathrow are playing a much cleverer game – we've never seen this sort of approach. For us, it's a tougher and very different challenge."

Heathrow is also proposing a congestion charge for drivers going to the airport, in an attempt to address concerns about air quality. While Heathrow constantly breaches EU limits for nitrogen dioxide levels in the air, it stresses that road traffic causes similar pollution around London.

The charge would aim to keep car use at current levels, even if a third runway was built, although Heathrow says it would only want a scheme to be implemented once upgrades to public transport links had been completed – including Crossrail and a new link to the Great Western mainline.