Our last house had a smooth transition between tile and hardwood. It was built with the flooring in mind. I'm not sure how they did it but it looked great. Our current house has had the flooring redone in rooms by the previous owners. There's a noticeable transition between the tile and hardwood. I can't wait for it to be replaced with all hardwood. It seems inexcusable in a brand new house. Hopefully something can be done.

There is no transition. The carpet is loosened at the bottom of the step until the wood is in...then reattach the carpet and trim the carpet so that it just touches the wood. It will hide the expansion gap also. Very simple and as common as anything ever gets.

Hmmmmm....Stairs have as many as 15 different code requirements that need to be followed. That includes riser height, depth of tread, railing heights/lengths as well as the size of voids between balusters, etc. As SOON as you change the FINISH on the stairs you MUST bring the stairs up to current code. And THAT can get expensive...depending on how old/bad the stairs are to begin with. The 'stair treads' you are purchasing are just shaped pieces of wood. The STAIRS themselves are the thing that carry 'the code'. Stairs with CARPET can be RECARPETTED without worrying about code. As long as you replace like-with-like you should be OK. And yes, your contractor MUST follow code. How else do they get permits for things? Your contractor *should know this. But MANY do NOT. And I mean FAR TOO MANY do NOT know this. That's why a finishing carpenter is required to deal with stairs...and the contractor's bid *should have included that EXTRA cost...which is why most of them do NOT bring in finishing carpenters. It costs them TOO MUCH MONEY (and homeowners have a tendency to pass out when the see the costs...it just gets ugly). Please post a photo of what you have right now....it will help us help you.

agree with @millworkman or get a piece of marble threshold at your local home improvement store... in anycase, you will need a carpenter with tools and skills!