Ed and Pat Harman were away on holiday when the private twin-engined Cessna jet crashed into their house in Farnborough, Kent.
All the plane’s five occupants were killed.
“There would have been no chance if they had been in the property, and on a normal Sunday afternoon they would have been about,” their son Peter said.
“If it had been an hour earlier, my mother, brother and his partner would have been inside the house.”
“To us, it’s just bricks and mortar. We’re thankful they’re alive, they’re thankful they’re alive,’ he added.
Meanwhile, two more victims of Sunday’s plane crash were named yesterday.
Sources said Christopher Allarton, 25, and Michael Chapman, 57, the private jet’s co-pilot, were among the five men killed in the incident in Farnborough, Kent.
Crash investigators have begun examining wreckage at the scene.
No “black box” flight data recorder was fitted to the plane, however, which was privately registered, the Air Accidents Investigation Branch (AAIB) said.
The plane crashed into a house in a cul-de-sac and burst into flames but nobody on the ground was injured.
Eye witnesses said it was a “miracle” more people had not been killed but said the pilot appeared to make a desperate bid to avoid houses in the cul-de-sac.
They described seeing panic on the faces of those inside the plane before the twin-engined Cessna Citation clipped a building and crashed.
Tributes were paid to two of the dead, David Leslie and Richard Lloyd, who were popular figures in the world of motor racing, while the pilot Mike Roberts was hailed as a hero for attempting to steer the stricken aeroplane away from houses.
Former Formula One driver David Brabham, who raced with Mr Leslie, said: “David was a great guy. He was a very good driver and a distinguished gentleman.
The business flight had taken off from Biggin Hill Airport and was heading to Pau, in south west France.
It was only five miles from the airport when the pilot put out a mayday call and it was just two miles north of the airport when it crashed.
Mr Lloyd was the owner and manager of the Apex Jaguar racing team, which competes in the FIA GT3 European Championship, and it is understood he was travelling to the Nogaro circuit in south-west France for pre-season testing.
Mr Leslie was Scottish karting champion five times before winning the Formula Ford title in 1978. He had spells in Formula Three, Sportscars and Thunder Saloons before spending over a decade in the British Touring Car Championship (BTCC).
He won nine BTCC races, finishing second overall in 1999, and continued to race until his death.