It may be possible at lighter weights to ascend vertically to 1000ft but vertical ascents involve a considerably higher risk than the normal takeoff technique you are witnessing. It sounds as if your neighbour is doing is what most single engine aircraft pilots do when possible, that is takeoff keeping suitable landing areas in close range as long as possible. Best thing would be to go & talk to him/ her about it, most pilots are happy to talk about what they do & why they do it.