Can I claim the single apartment exemption if I own a home abroad?

Generally no. Since the 2013 tax reform, non-residents seeking the patur dira yechida (single apartment exemption) must declare under oath that they have no residential apartment anywhere in the world — not just in Israel. If you own or have rights in a home in your country of residence, you will not meet this condition and the exemption will not apply. There are narrow exceptions and edge cases, so it is always worth reviewing your specific situation with a tax attorney before assuming the exemption is unavailable.