I would like to add some recessed lights above our couch. How to connect power to them when there is a second floor?

I'll begin the weigh-in.

You have a lot to consider... for instance, have you already thought about the circuit? Light cans, depending on the trim kit and the size, can hold up to 150W bulbs, or so.

Do you want these cans controlled by a wall switch that currently operates an overhead light / fan, or will it be controlled by a new switch?

You mentioned a second floor above the cans, do you have basement access below the wall where the switch is located? Is your power routed through the basement?

Thanks for the questions Bart87, there will be a new switch put in. There's a crawl space under the house. How would I run power from the cans to the switch when there's a second floor with no access between?

If the fixture openings are close to each other and in line, you can use a 4,5, or 6 ft long drill bit , Greenlee makes one, to drill across joists, if needed.

Once you get to where the wall and ceiling meet, there usually a double layer of stud, and you will need to channel the drywall to drill up through this member to get up into the bay in line with the lights, to get the wire down into the basement.

Or,it is possible to couple two long drill bits together and drill up from the basement to drill through this upper member.

Locate the channel and drill up from the basement into that bay of the partition, and drop a string with a small amount of chain, you can hook the string and chain from the basement.

Then rise up from the basement into the switch using the same method.

There are "Old Work" type recess housings,designed to be installed completely through the fixture opening of 6 inches.