Usally the top is left open. But if light is a issue, you can have a cellular shade made to fit into the opening. Cellular shades work out well on this type of window. You can get either one to cover both windows for a clean look, and better light control. Or 2 so you can have one up and one down if you want.

I have a window that is about 114 inches wide (made up of 3 windows like yours), maybe about 54 inches long as well. I currently have wood blinds, outside mount, and I do NOT like them. I am going to replace them with curtains . . .I just need to sew them! Here is why I don't like them: (1) You will be getting 3 different blinds, one for each window. There is no guarantee that the blinds will match up perfectly. I called the co. to complain, and they said it can be off within a certain distance per their standards, and if it exceeds that, the would replace them . . .but it was within that range, so no. (2) Open, the outside mount doesn't look so bad. Closed, yuck! I think it looks messy. (3) On a large window, it's a whole lotta blinds going on. Very, very angular, a lot of lines. If you were going with an inside mount, at least you could put curtains up to soften the edges, but with an outside mount-- not so much. On mine, the blinds are connected to something that looks like moulding, so I guess you could put up a rod that projects past that for a valance, but like I said, with an outside mount, panels would be harder. Just my 2 cents. I know some people who visit LOVE my blinds, so who knows. When I got them measured, I had it done professionally. People will come and give you free estimates and do measurements then.

I purchased the Marvin Utimate casements too and finding it difficult to find window treatments that fit inside these windows.. The grooves inside for their integrated shades prevents mounting of conventional window treatments using an inside mount. I also purchase a couple of Marvin Ultimates with the retractable screen and there does seem to be a Marvin solution for an integrated shade with it either. Anyone have a suggestion on this? I figured it out!. You do an inside mount on 1" part of the surrounding window inner surface.. It might leave a little sticking out depending on the 1" depth mini bind or cellular shade, but it is doable.

eld6161.........thanks. I too am in Florida. My second shutter vendor was here yesterday to measure and price, etc. The first told me I would find the slider "cumbersome", the second disagreed....and offered a reg. slider or a bi-fold slider. Did you have that option and did you use a bi-fold design anywhere? I do see where it would allow in more light, balance the visual appearance of the door when both open, but I hadn't even been expecting that option and I am typically NOT a bi-fold fan.....thx for any additional info you can share.