This is the house of Yeo Woon-gwang (Park Sung-woong) in Man to Man (맨투맨) (JTBC, 2017) — as seen in episode 3 for instance.
This also appears as Hyun Ki-joon’s (Kang Ji-Hwan) mansion in Lie to Me (내게 거짓말을 해봐) (SBS, 2011).
This mansion is located in Seoul’s neighborhood Pyeongchang [Pyeongchang-dong/평창동], in the Jongno District [Jongno-gu/종로구].
41 Pyeongchang 5-gil, Pyeongchang-dong, Jongno-gu, Seoul
서울특별시 종로구 평창5길 41
(서울 종로구 평창동 537-14)
Geolocation: 37.614200, 126.965559
Hongje Station [홍제역], Seoul Subway Line 3, Exit 1 or 2
(Prepare for quite a walk or take a taxi.)
— submitted by old.fred23