Do Your Shelbyville Windows Need Inside Mount or Outside Mount Blinds?

Shelbyville Window Treatments · 2026-09-22

Nobody grows up knowing the difference between inside mount and outside mount, and there's no reason they should. It's a decision that only matters the day you're ordering window coverings, and by then most Shelbyville homeowners have already spent more time picking a color than thinking about how the hardware actually attaches.

Inside Mount and Outside Mount, Defined

The short version: inside mount fits inside the window frame, outside mount covers the frame from the wall in front of it. The long version depends on which rooms you're outfitting, because the right mount tends to follow the room's actual job more than any general rule.

A living room window with good trim usually wants to show that trim off, which points toward inside mount. A bedroom window that needs to go dark at 6 a.m. in June usually wants full coverage, which points toward outside mount. Neither preference is wrong. They're just answering different questions.

Before either decision matters, though, the window has to physically support it. A Shelbyville home can have plenty of rooms where the frame simply doesn't have the depth for inside mount, which means the room-by-room preference only applies once the depth question is settled first.

Why Homeowners Choose Outside Mount

Ask yourself first whether the frame even has the depth for inside mount. If it doesn't, or if a crank handle or lock is sitting where the hardware would need to go, the decision's already made for you and outside mount is the answer regardless of preference.

Beyond that forced case, ask how much light control actually matters in that room. A bedroom that needs to go properly dark benefits from outside mount's ability to fully overlap the frame and close the gaps that inside mount leaves open. A home office or a dining room usually doesn't need that same level of light blocking, which is why outside mount shows up more often in bedrooms than anywhere else in a typical Shelbyville house.

Last question: is the frame square? Older homes especially can settle unevenly over the decades, and an out-of-square opening is much easier to work around with outside mount, since the header mounts level above the window regardless of what the frame underneath is doing.

Why Homeowners Choose Inside Mount

The appeal is mostly visual. Inside mount keeps your trim doing what it was built to do, framing the window rather than disappearing behind hardware. On a window with detail worth showing, whether that's original woodwork in an older Shelbyville home or nicer trim added during a renovation, inside mount is usually the instinct, and it's usually the right one when the frame allows it.

It also sits closer to the glass, which matters in rooms where anything hanging further out would be in the way. Kitchen windows over a sink are the classic example. A faucet or a window crank can make outside mount hardware awkward or even impossible to clear, and inside mount avoids that problem by staying within the opening itself.

The honest tradeoff is a light gap along the edges, sometimes a half inch or more depending on the product, since the shade has to be built slightly smaller than the frame opening to physically fit inside it. For a home office or a living room that's a non-issue. For a bedroom where you want it fully dark, it's worth seeing that gap in person before you decide.

Mixing Mounts and Getting a Consistent Look Room to Room

Here's something most people don't think about until they're halfway through an order: you don't have to pick one mount for the whole house. A Shelbyville home with deep, original wood frames in the living room and shallower frames in the bedrooms might reasonably end up with inside mount in one room and outside mount in another.

What matters more for a consistent look is keeping the headrail style and color similar across rooms that are visible from each other. An open floor plan where the kitchen and living room share sightlines looks better with coordinating treatments even if the mounts differ.

Within a single room, though, try to stay consistent. A row of three windows on the same wall with one inside mount and two outside mount will look like a mistake even if each individual choice was correct for that window. If one window in a group genuinely can't take the same mount as its neighbors, it's worth discussing the tradeoff before ordering rather than after the boxes arrive.

Inside or outside, the right mount depends on details a photo can't show you. A free in-home measure covers the depth check, the trim question, and the obstruction check in one visit, so you're not making a permanent decision off a guess.

Depth, Obstructions, and Other Mounting Realities

The number that actually settles most inside versus outside arguments is depth, not opinion. Faux wood blinds generally need 2 to 2.5 inches of clear space. Cellular shades can sometimes fit into slightly less. Shutters are the pickiest, usually wanting 3 to 3.5 inches because the panel frame itself takes up real room.

Here's where the idea of easy DIY measuring falls apart a little: a tape measure alone won't catch everything. A crank handle sticking into the frame, a sill sloping toward the glass, trim that's been added since the original window went in, all of these can rule out inside mount on a window that measures deep enough at first glance.

None of these problems are rare. They show up often enough that a professional measure exists specifically to catch them before an order goes in, rather than after a custom product arrives and doesn't fit the way it was supposed to.

Frequently Asked Questions

Do inside mount blinds work on windows with deep trim?

They can, as long as there's enough clear depth behind the trim for the headrail and the tilt mechanism. Deep trim by itself isn't a problem. What matters is what's actually inside the opening, not how the trim looks from the front.

Will outside mount cover up decorative trim I want to keep visible?

It can, since the headrail sits in front of the frame rather than inside it. If you've got trim you want to keep showing, that's a real point in favor of inside mount instead.

Can a window be too shallow for any mount at all?

Almost never for outside mount, since it doesn't rely on depth inside the frame at all. Inside mount is the one with real depth limits, which is exactly why outside mount exists as the fallback for shallow windows.