In broadest terms, the narrative is written from the third person point of view. There are times when that point of view is quite objective, recounting events as the characters experienced them. There are also, however, several occasions when the author inserts commentary and/or observations about the characters' experiences, both in the moment they're being described and at points later in the characters' lives.
On another note, the narrative frequently shifts back and forth between the focus of its point of view. Specifically - Parts 1 and 3 focus on the present on the characters of Leopold and Henrietta. It's important to note here that within each part, the narrative at times shifts still further, narrating events from Henrietta's point of view in one chapter, in Leopold's in another, and in Part 3 shifting again to narrate from Ray's point of view. Part 2 focuses on Karen and her point of view; there are few, if any, internal shifts of point of view in this part. The point of view is exclusively Karen's, creating the sense that it is her story and her experiences that are ultimately central to the novel's overall thematic and narrative intent.
The House in Paris