Get unfinished wood in the same species as you have in the other space than have it finished to match that is always the best way to go I would probably also do the sam kind of flooring as the other to avoid issues.

The trend is to have one flooring throughout so the house feels more unified and spacious. Your current floors are oak- readily available and relatively inexpensive, match them. It will be your best investment.

you will never be able to match the new with the old unless you buy the same wood species and refinish the old. you will still have a difference where they are butted into the new, unless you have them weave them together (which would be nice to make it look seamless throughout the home)

engineered is great, but Oak hardwood can be sanded and finished to suit your needs.

Do it right from the jump and you will be pleased with the results.

We added new flooring next to 25 year old flooring. The installer/ finisher did an excellent job matching the woods. I recommend hiring a professional flooring installer and not a ” handy man”.

Thank you to each person that submitted advice! I’m most appreciative and also impressed with the quick response. I’ve taken it all to heart!