I live near Heathrow and bought my house in 1986. I got copies of the official approach and departure tracks (I still have the dye-line print) to make sure I was away from the flight paths. An ATC told me they were very unlikely to change. In 1986 there were very few flights after 8.30 pm at night. Since that time the departure tracks have changed and the number of flights has increased by 50%. Most of the extra flights are in the early morning and late into the night.
When I bought my house aircraft noise (and pollution related to the airport) was not an issue for me.
Please can we drop the argument that says 'you bought there so it is your fault'? When I bought it was reasonable to assume I would not be bothered by airport noise. I am. The air was clean. Now it is not.