This house is located in Omaha, Nebraska Penny's childhood home. The house is a farmhouse and Penny grew up here with her father, mother, sister and brother.
The house is likely first seen in "The Staircase Implementation" where Penny's bedroom is seen and she is seen as a high-school girl taking a homemade pregnancy test with a guy sitting next to her and she was relieved to not be pregnant.
The house was seen again in "The Bachelor Party Corrosion" where Penny's father was shown in the house's living-room.
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Penny likely in her room is relieved to not be pregnant
Wyatt in the living room