Collinwood Mansion

Board,

Someone please help me with this question.
The revival series was filmed at an mansion in Beverly Hills, California.
My question is was the interior set of the Collinwood mansion, the actual interior of the mansion that the series was shot in? Or was it just an elaborate expensively constructed set on the backlot of a studio?
I ask because in episode three, young David Collins, enters into Collinwood at sunset and encounters three female vampires, that chase him through the Collinwood hallways and rooms. Before this scene, is shown, David Collins, enters into the mansion, asking out loud where is everyone at in the mansion.
When he is speaking outloud, you can hear is voice echoing throughout the mansion's corridors and hallways. This indicates that the mansion is very very huge, to echo sounds like that reverberating through the corridors of Collinwood. So, I am assuming it is the actual interior of the mansion, that was used as the interior of Collinwood, and not a sound stage or set.
Those echoes of David Collins, inquiring where is everyone, as he walked around the foyer and corridors of the mansion, are to genuine to be a sound effect.
Does anyone agree or disagree?

Anthony Cashmere

It isn't fair, using the living, to bring back the dead!!!-THE SCREAMING SKULL