What you're looking for is a Startrek transporter. A mechanical device that precisely devoted would take up so much space in the building it would make the architecture impossibly expensive. A reasonable compromise for long horizontal distances is the moving sidewalk found in airports. You might get by with a wheelchair that can climb stairs (they exist) but, in the long run, your legs would probably atrophy.

Not a transporter, but more like a cablecar, which is a ral system, either hanging from the ceiling or depressed in the floor, with stations every 30-50 Metres or so, and under/overpasses between stations. Maybe have two tracks with a car that goes each way.

The moving sidewalk of airport fame is still the best solution, and a damn fun one too.

It already exists. There is one right outside my window.

It's called a "tram" (though there are other variants known as "bus", "metro" or "people mover").

It solves the horizontal problem, but you do have to change vehicles to do the vertical movement!It's very convenient. It stops at the kerb right outside the front door of my local supermarket, no car park to walk around, and drops me 150 Metres from my front door!:-)

I think rainwhitefang is talking about a system with horizontal and vertical tracks for an elevator.

I see a major problem- there is now instead of an elevator shaft an elevator plane in the building, which cannot be crossed by corridors and makes emergency exit more difficult.