Tuesday 25 October 2016 3:12 pm

This is how the third runway at Heathrow will hit London house prices

The government has given the go-ahead for the third runway, and if there's one group of people who won't be happy about it, it's the people living nearby.

Estate agents eMoov think the decision could lead to a 20 per cent drop in house prices in the area due the noise and air pollution that the project will bring.

Read more: The best reactions from MPs to the government's Heathrow verdict

The runway decision could create London's first affordable pocket for housing – the average house price in Hounslow and Hillingdon could fall to around £330,000, eMoov said. At the moment, the average house price in Hounslow is £407,666.

Areas nearer the centre of the capital will also be affected, including Richmond, Westminster, and Hammersmith and Fulham.

The decision could be the "final nail in the coffin" for house prices in Westminster, eMoov said, where prices have fallen by £65,000 in the last month.

Read more: Gatwick boss: Heathrow isn't the right answer for Britain

Russell Quirk, founder and chief executive of eMoov, said: "Great news for the UK economy and indeed those that frequently fly out of London for both business and pleasure.

"Not such great news for the hundreds of residents that will see their properties demolished as a result of the expansion of a third runway."

Ben Madden, managing director of west London estate agents Thorgills said:

Potential buyers will be forensically poring over flight paths to see if that once quiet street will be blighted by aircraft noise.

Aircraft noise in West London is already the property currency. A two-bed house in an area that’s overflown will have a negative value difference of up to 10 percent to a similar property in an area nearby. A third runway could wipe tens of thousands of pounds off prices.

Some 783 homes will be demolished to make room for the runway, removing communities in Longford and Harmondsworth.

The government said today that it will be giving homeowners faced will compulsory purchase 125 per cent of the market value of their properties, plus stamp duty and other fees.

Read more: Boris Johnson says third runway at Heathrow "will be stopped"

Rob Weaver, director of investments at Property Partner, said: “The creation of construction jobs in the short-term, airport jobs in the long-term – and all the nearby secondary industries (such as hotels), will push up employment and property prices. I personally live near the area, and my house is under one of the flight paths, but I still believe that there will be far more winners than losers."

Mark Hayward, managing director of the National Association of Estate Agents, said worried homeowners shouldn't act too quickly. 

"Alongside today’s announcement, the government has also released details of a fresh consultation, while the threat of judicial review still remains high," Hayward said. "This means homeowners that will be impacted by the extra runway should not rush into making knee-jerk decisions, as they have time to assess their options."

Sam Bowman, executive director of the Adam Smith Institute, said "we shouldn't feel too sorry for local residents".

Bowman said:

Their house prices will have been lower to reflect the inconvenience of living in the flight path, compared to similar houses in quieter areas and, for anyone who has bought a house in the past four decades, also to reflect the probability of a third runway being built. 

So the trade-off for them is cheaper housing in exchange for a bit more ambient noise from aircraft.