How to flood-proof a home: 'after a storm swamped my basement flat I renovated so it wouldn't happen again'

It had started out like any other ordinary weekday afternoon. Christoph Halstenberg was working in his makeshift home office — previously known as the garden shed — and it was raining.

“It was pouring for about two hours,” he said. “I was trapped in the shed until it stopped and when I came out I noticed that there were big puddles everywhere.”