Inside mount and outside mount describe where a window shade is installed in relation to the window opening. The choice affects appearance, coverage, measurements and which installation systems are compatible with the window.
What is an inside mount?
An inside-mount Roman shade sits within the window opening. This creates a neat, built-in appearance and leaves more of the surrounding trim visible. It is a popular choice for custom shades when the window has enough usable depth for the mounting system.
What is an outside mount?
An outside-mount shade is installed over the window opening rather than within it. Depending on the window and product, it can attach to the wall or trim area. Outside mounting can increase coverage around the edges of the opening and is useful when the window recess does not provide enough depth for an inside mount.
Which looks cleaner?
Inside mount usually creates the most integrated appearance because the shade sits within the frame. Outside mount can make the window treatment appear larger and more prominent, and it can visually change the proportions of the window.
Which gives better edge coverage?
Outside mount can provide more overlap around the opening because the shade can extend beyond the window dimensions. With inside mount, the shade must fit within the opening, so small edge gaps can be a normal result of the fit and operating clearance.
What about no-drill shades?
Many no-drill systems are designed around specific inside-mount conditions. The window needs enough depth and a compatible frame for the mounting mechanism. Do not assume every no-drill Roman shade fits every window.
Browse our No Drill Roman Shades and check the individual product requirements before choosing a mount type.
How to measure for inside mount
Measure the inside width and height of the window opening using a metal tape. Check the width at more than one point because window openings are not always perfectly square. Follow the exact deduction or ordering instructions shown on the product page rather than making your own adjustment unless the instructions specifically tell you to do so.
How to measure for outside mount
For outside mount, you are measuring the area you want the finished treatment to cover. Think about how much overlap you want around the opening, whether there is trim, and whether handles or other hardware interfere with the shade.
Use our full How to Measure for Custom Curtains & Window Shades guide before ordering.
Quick decision guide
- Choose inside mount for a recessed, streamlined look when the window has enough depth.
- Choose outside mount when you need more coverage or the recess is too shallow for the desired system.
- Choose a compatible no-drill inside mount when avoiding permanent holes is a priority and the window meets the product requirements.
Once you know your mount type, compare Roman Shades, No Drill Roman Shades, and Blackout Roman Shades to find the material and light-control level that fit the room.