They don't feel connected to the deck on the left, so I voted centered.

The lower level "greenhouse" is shifted in the images, so it's not a fair fight.

RappArchitecture, which location of the greenhouse do you prefer?

How about showing the whole house. This should be decided on a whole, not in a vacuum. What is the lower patio being used for? Are there views you are trying to maximize? Is the yard flat? What direction does this all face?

millworkman, great questions, I appreciate your desire for more details! The thing is none of this really exists at the moment, we are going to be doing a complete overhaul to the backyard.

• The backyard faces south and looks at a lake so we want to enjoy that view as well lake activities like kayaking.
• The yard is not flat, it slopes down from the house to the lake.
• Currently there is no lower patio, we will be excavating and creating a walkout basement that will lead to this new lower patio. The deck above will be constructed to "weatherproof" the patio below so we can hangout there even if it's raining and have lights and fans. I'd like to have a fireplace in there to extend using this space even when it gets cool out. We are also looking into phantom screens so we can screen in this area to protect from bugs as necessary. We want to hang hammocks in this area too or on the deck posts. So mostly this space is for hanging out and relaxation.
• The yard that is left will be leveled near the lake so it is more functional.
• If you are looking at the house from the lake, the garage is on the left side (where there is a door and no windows in the renderings) and there is currently a pathway to the left of the garage that leads from the driveway to the backyard. This is one argument for having the stairs on the left as it could provide a straight route to get down to the lake. But more often than not we would be entering the top deck from one of the sliding doors.

" The thing is none of this really exists at the moment, we are going to be doing a complete overhaul to the backyard. "

Is the house there? If so, walk down to the lake, turn around and take a couple of pictures. That will be better than the half baked rendering.

Left, for the reasons Kendrah stated. Not only does the center stairway chop the deck in two, but the narrow area there looks like a painful chokepoint. That door is going to constantly thwack people who are trying to cross from one side to another. Perhaps while they are carrying food or beverages.

I like the stairs on the left because it gives good clearance around and access into both sides of the greenhouse.

Stairs on the left looks more balanced. And they would be less likely to block lake views (and/or sunlight to the greenhouse) on th left side.

It's not a question of what I prefer, it's what works best for the overall layout. Which you haven't shown so we can't comment. I think that would have an impact on where the stairs are.