He's aged 32 and single on the 1911 census.
others on the census return are his house-keeper and two servants.
He was born about 1879 in Coleraine,County Derry.
He appears on the
absent voters list (WW1) as a Lieutenant in the Royal Army Medical Corps. He must have served overseas post 31/12/1915 as he is entitled to the British War Medal and the Victory Medal. (his rank on the medal index card is Captain)
It's quite possible his WW1 service papers have survived at the National Archives, which should show next of kin.