Almost every house has a room like this. A room that never feels as warm and comfortable as the rest of the house. The thermometer shows the right temperature, the heating system works as it should, and yet that particular room feels colder than the rest of the house.
For some it's the bedroom. For others it's the bathroom, home office, basement or an extension. In many cases it's not a matter of the house lacking heat. The problem is instead that the room's conditions are different from the rest of the building.