I have known many people who killed themselves with a firearm, including some of my relatives, and none of them ever worried about doing it outside the house: many did it while their family members were present in other rooms. My uncle, for example, after a previous suicide attempt by cutting his veins which failed, as he had been saved and still had the bandages shot himself in the cellar of our mountain house, while we relatives and cousins were upstairs. We heard a gunshot, then a second one: he and a friend of his killed themselves one after the other. My uncle had aimed the shotgun more or less above his ear, I don't know about the other man, but when we went downstairs they were both already lifeless.