The first time Sally goes to school she leaves the house with her hair in a pony tail, but when she's filmed inside the school bus her hair is down.
In the opening scene when the men are unloading the vehicle, in the background you can clearly see one house has a satellite dish and later on another house is seen in the background with a UPVC extension, both not available at the time the film was set
When the family are driving towards the start of the film, they pass a blue modern shaped car with body tone wing mirrors which can be seen through the windows of their car.
In the hallway of the house there is a metal and glass telephone table attached to the wall but there is no telephone, which would have been a rotary dial type telephone. Upon it sits a glass clown which was popular in the seventies, they were usually on the fireplace.