Researchers at the University of Cologne investigating the impact of short-term rentals on the Cologne housing market have released their findings with a stark warning to other urban areas.

The study found that short-term rentals cause housing shortages and rent increases, and that the number of short-term rental accommodations in Cologne had increased from 500 to nearly 6,200 in just five years.

Of these accommodations, 41 percent are rated as professional, of which 65 percent are owned by hosts with multiple accommodations.

The research also found that 14.2 percent of overall rent increases within the study period can be attributed to short-term rentals, driving a rent increase of approximately 320 Euros per year for new tenants.

Researcher Felix Mindl said: 

“While a large proportion of hosts can be considered home sharers, we find an increasing proportion of providers who have developed a professional business model from short-term rentals. Professional short-term rentals are available to tourists throughout the year and thus compete directly with long-term tenants, for whom the rooms are then no longer available.”