I've finally tracked down the house used in the Secret of Parker House episode.
It's called Aberthau House (formally known as Rear House). It's a heritage mansion located at 4397 West 2nd Avenue Vancouver, BC.
Wikipedia entryYou can see exactly where it is in our
locations mapI've tracked down some pictures of the house in google and posted them in
the galleryAnd of coarse, it's been added to our
loacations page