Plus the extra heating/cooling needed.

My friend says all the heat rises up there, and it's uncomfortable and hard to control upstairs.

Trust me - it's loud enough with it closed off. I was surprised how much the noise transfers. It's not unbearable but it's definitely not quiet.

This is our layout - sounds similar to yours and it travels right down the stairs - and right up the stairs. My son's room on the far right is much quieter than my son's on the left - notably so.

I'm not a fan of open balconies, especially if there are bedrooms nearby. The only time I really love a vaulted space with an overlooking balcony is in a lodge type home. Think big beams and rustic, maybe even actual logs. I think the noise will be an issue with bedrooms.

Another vote for closing it off. We avoided any sort of open, two story spaces in our new build. In our current house we have a two story foyer and it is awful how the noise carries upstairs. I can't imagine having it open to the great room.

I have a two story foyer and great room and the hallway on the 2nd floor is open to both. Never had an issue with noise or heating issues. This arrangement actually brings a lot of light into the house because both the foyer and great room have plenty of windows.

I vote to close it off for all of the reasons previously stated. Besides, I find that setup to look quite dated, straight from the late 1990's & 2000's.

Close it off. You will see them running back and forth to the bathroom, in various stages of undress, when you're entertaining, all the noise in the great room will be magnified and it will be hot up there.

They make for uncomfortable noisy spaces.

I prefer closed too, in our upcoming built we eliminated any and all two story features inside including foyer, but it's a personal preference.

We have windows on our stairwell and that lights up the stairwell and landing nicely.

Make sure the railing does not have a flat top. This will aid to increase their balance and coordination when they play "Tight-Rope" on the railing.

I like ours but cats have 9 lives...

Extra padding under the carpet on the first floor may not be a bad idea.

Haha! Love everyone's responses. Thanks for all your input. I think we'll wall it off. We considered that after the kids are older we can always open it up if we want to.

Just try to imagine what you are going to do to cover that massive wall up there. Just paint and nothing else makes for a big dull wall. And if the plan was meant to have it open, you may have created a dark long hall.

I totally agree with hating the 2 story room with a catwalk (what we call it). But closing it off may be pretty bad also. Decorating a 2 story room is a challenge and closing it off adds another huge bland wall.

Consider getting rid of the 2 story room completely. It looks grand and gives a lot of light. But has so many downsides that will live with the house forever.

We have a 7 yo and like "The Walking Dead" - just another consideration beyond noise. When we happen to hear his door open (almost never), the run to the remote is fast and furious. But hey if you absolutely never watch things that is inappropriate for kids.....

I'd consider closing it off and then doing a vaulted or cathedral ceiling in the great room instead of a 2 story height. More interest vs. a 2 story wide elevator shaft.