Inside mount vs outside mount: which is right for your window?

Inside mount and outside mount are the two ways to install a window treatment. They look different, perform differently, and cost roughly the same. Picking the wrong one wastes hours of installation time and sometimes a remake.

What "inside mount" means

The blind, shade, or shutter sits inside the window frame, recessed into the opening. The window trim stays visible around the edges. This is the cleaner, more architectural look — favored for new construction, contemporary homes, and rooms where the window trim itself is decorative.

What "outside mount" means

The treatment covers the window opening and the trim around it, mounted onto the wall or the trim itself. This hides the window frame entirely. It's the blockout-friendly option — no light gaps at the edges — and the easiest to install on irregular windows.

Side by side

Factor	Inside mount	Outside mount
Look	Cleaner, more architectural	Bolder, hides the trim
Blockout	Some light gaps at edges	Full blockout (with overlap)
Depth requirement	Min 2" of window depth	None
Works on irregular windows	Difficult	Easy
Easy to install	Slightly harder (must be precise)	Slightly easier (more forgiving)
Cost	Same	Same
Best for	Living rooms, dining rooms, new construction	Bedrooms, nurseries, blackout needs

How to decide

Bedrooms and nurseries → outside mount. You want full blockout. Inside mount always has small light gaps at the edges; outside mount with proper overlap (1.5 inches each side) eliminates them entirely.

Living rooms and dining rooms → inside mount. Cleaner look, the trim usually adds to the architecture. Light gaps don't matter when blockout isn't a priority.

Shallow windows → outside mount. If your window opening is less than 2 inches deep, an inside-mount blind sticks out into the room. Just use outside mount.

Irregular windows → outside mount. Old houses, arched windows, and windows that are slightly out-of-square work much better with outside mount. You don't need the precise inside-frame measurement.

What about combining both?

Yes — many bedrooms use an inside-mount blackout roller shade plus outside-mount drapery panels over the top. The shade does the blockout work; the drapery does the visual softening. It's the most upscale residential pattern.

Once you know which mount you want, open the configurator — mount is one of the steps, and the AI preview shows the result either way.