The number of vacant apartments in the country rose to 51,172 as of June 1st, a 12 percent increase from the same period a year earlier, the federal statistics office said.
That translated into a vacancy rate of 1.19 percent, compared to 1.08 percent in the same period for 2014.
The majority of the vacant flats (40,202) were for rent, while 10,970 were for sale.
Increases in vacancies were recorded in all of the country's seven major regions, with highest rises seen in northwestern Switzerland, followed by Ticino and eastern Switzerland.
The canton of Jura registered the highest rate of empty flats at 2.35 percent, while the canton of Basel-City had the lowest rate at 0.34 percent.
In the city of Zurich, the vacancy rate was well below the national average at 0.22 percent, unchanged from a year ago.
In the city of Geneva, the rate eased to 0.5 percent from 0.43 percent, although it was lower in most surrounding municipalities.
The number of vacant single-family homes nationally also rose as of June 1st to 6,416, 14 percent more than a year earlier.