I wonder if you are familiar with the French film "Lettreville". It is quite an old film (from 1978, I believe) so maybe you are not aware of it.
The story is based on real events, although I think some licence has been taken. The film centres around one of the temporary towns built in post-war France to house people who had been displaced by the fighting. These towms were intended as temporary residences until families could be found proper homes elsewhere in the country.
It wasn't only the residents who were transient. The majority of the buildings were also intended to be taken apart brick by brick and relocated in other parts of France. In fact Lettreville was never intended to be a permanant settlement and only existed for 23 years, the final building being removed and relocated at some point in the late 1960s, although the town's foundation stone was left in place.
Residents of these temporary towns were moved to their new homes by the postal service, often delivered in vans carrying sacks of mail.
The film focuses on the last family left in Lettreville and the french government's efforts to move them. The family are driven to various locations in postal vans, but nothing is suitable. Then the Matriach of the family says that she will miss her house and could never leave it. The government offer to move the house with the family. Then one of the old men says that he will miss the park across the street. The government offer to give the family the park if they will leave. The children celebrate when the local school is demolished and carted off elsewhere but are less than pleased when the sweetshop goes the following week. It's a kind of gentle comedy.
Apparently there were 14 towns like Lettreville in France. Outside of Rouen there is a model village of Lettreville itself. The ticket office and cafe is an original building from the town. If you become a patron of the model village, it's owner will make a small figure in your likeness, who will live somewhere in the village. When you die he will either bury it in the churchyard or cremate it, according to your instructions. Interestingly, mail addressed to Lettreville is now re-directed to the model village.
I have brought Lettreville up because I think there were a number of these temporary towns in England, constructed to house people made homeless in the blitz. These towns no longer exist, the people having moved on and the buildings having been demolished or dispersed around the country. The only evidence they ever existed at all is their postcodes which are still listed by the postal service.