The estimated number of vacant homes in Japan stood at 9 million as of Oct. 1 last year, hitting a record high, an internal affairs ministry survey showed Tuesday.

The preliminary figure jumped by 510,000 from 2018, when the previous survey was taken, and doubled from 4.48 million in 1993.

Meanwhile, the total number of homes went up by 2.61 million from 2018 to 65.02 million.

Vacant homes accounted for 13.8% of the total, also marking a record high.

As the key reason for the rising number of vacant homes, the ministry's Statistics Bureau pointed to an increase in cases in which the homes of elderly people living alone become vacant after they die or move into care facilities.

Of vacant homes, those not serving any specific purpose, including for rent or sale or as second homes, numbered 3.85 million, up by 370,000. They accounted for 42.8% of the total number of vacant homes, increasing steadily since 2003, when the share stood at 32.1%.

The share of vacant homes was highest in Wakayama and Tokushima prefectures, both at 21.2%. Yamanashi Prefecture followed at 20.5%, partly because there are many second homes in the prefecture, which neighbors Tokyo.

In terms of vacant homes without a purpose for use, Kagoshima Prefecture had the biggest share of such homes at 13.6%. Next came Kochi Prefecture at 12.9%, followed by Tokushima and Ehime prefectures both at 12.2%. The shares were prone to be bigger in western Japan.

The research has been conducted every five years since 1948.

This time, the ministry surveyed 3.4 million houses and households to give estimates across the country, covering only homes where people can live. Dilapidated buildings at risk of collapse were not surveyed.