Whilst there, Del overhears Lord Ridgemere haggling with someone on the telephone about the cost of cleaning their two priceless Louis XIV chandeliers.

Seeking opportunity, Del tricks the Lord into believing that chandeliers are the Trotters' family business and agrees to carry out the necessary work at a low price.

Grandad goes upstairs to unscrew the holding bolt for one of the chandeliers while Del and Rodney climb up on step ladders with a blanket ready to catch it.

David Jason and Ray Butt agreed that the storyline ought to be used, meaning Sullivan had to write the script backwards, starting with just the end point and then working out how the Trotters would come to be in a mansion.

It was initially intended that this would be the final scene in the episode, so after the incident Jason and Lyndhurst were required to stand and stare at each other in silence for 30 seconds while the camera rolled.

Many of the cast and crew struggled to contain their laughter in the aftermath of the shot; Butt himself stuffed a handkerchief into his mouth and left the room.

The school would not give permission for any of its floorboards to be pulled up, however, so the scene with Granddad undoing the fastening nut was filmed in a house belonging to Ray Butt's girlfriend.