For Franziska Hilberath, whose home in western Germany's Ahr valley was destroyed by flash floods this summer, it was a Christmas miracle to be able to move into a donation-financed "tiny house" this month just in time for the holidays.

Hilberath and her partner have been sleeping at the homes of friends and relatives since Germany's most lethal floods in six decades in July that killed more than 180 people and destroyed many houses, roads, railway lines and bridges.

They were on the waiting list for "tiny houses" to stay in while fixing up their old, half-timbered house, where water had reached the ground floor ceiling when the Ahr River burst its banks in the wake of record rainfall.