The house

Actually, the interior shots line up very accurately with the interior of a real New York townhouse. The main staircase set off to one side, the parlor floor with the living room (with all the pop art) in front and the dining room (the game room) behind it. On the second floor, the front and back bedrooms off the hallway, with a bathroom accessible from both of them. The third floor having a guest bedroom in the front (where Lisa stays)and the maids room in the back. Then there is the street level (actually somewhat below street level) with the service entrance under the front stoop. We see this view just once, when the maid (who then goes on a 3 week vacation obviously a time chosen to execute the "game")accepts a delivery from Norman. He enters through this service entrance, then brings the groceries through a hall to the back of the house where the kitchen is. Yeah, the kitchen is great. More likely that the laundry would be in the basement, but it needs to be more accessible to wash the bloody sheets covering Norman's body. And when you exit the kitchen to the backyard there are a few steps up to the main patio, very accurately showing that the kitchen level is somewhat below grade. The elevator, which is really more of a dumbwaiter is also very accurate.

They do mention the address of the townhouse as 11 e. 63rd St. I've checked out that address and it doesn't match. In fact I've checked every street off of 5th avenue on the east side and I can't find the location. At the end, we see Lisa exiting the house from a high up shot, following her to 5th avenue, where we see Central Park on the other side. At least I think it's 5th avenue. The landscape does change in 45 years. I wouldn't expect them to use the exact address, but all indication are the street is the first block off a 5th ave. It's possible the street they shot on was in the e. 90's where a lot of the original townhouses were torn down to be replaced with hospitals. Or, the façade of the townhouse could have been altered beyond recognition. If anyone knows where the actual location is, please let me know. It's also possible that the interior shots were done in a studio. A townhouse might have proved to tight a space to film with those big cameras they used back then.

Yes, "Eye of the Cat" was shot in S.F. in and around a real mansion on Lafayette Park. You can see it today, looking pretty much as it did back then. And of course the hill that Eleanor Parker also sails down is still there. I believe the interior shots were done inside the house. Some of the architectural detail that is seen on the outside matches what you can see in the interior shots. Not likely they would have reproduced that for a set.

Though the exterior looks remarkably like Manhattan, it's actually the Upper East Side Street, ending at a faux Central Park, on the Universal backlot. It's been used in countless films. The real clue that it isn't Manhattan is that the same car is always parked in front of it.

You're confusing this film with another Universal potboiler, "Eye of the Cat" set in a great San Francisco house. Both films were made in the late 1960s using Universal contract players. In the case of "Cat" it was gorgeous Gayle Hunnicutt, who went on to marry David Hemmings but never became a big star.