Choosing between an inside mount and an outside mount is one of the most important decisions when ordering custom blinds or shades. It affects the finished look, the amount of light around the edges, and whether your window can still open freely.

This guide explains the difference, shows how to measure for each option, and highlights what to check for tilt-and-turn windows commonly found in Germany.

1. What Is the Difference Between Inside and Outside Mount?

An inside mount positions the shade within the window recess. This keeps the surrounding frame visible and creates a streamlined look, provided the recess is deep enough and the hardware fits.

An outside mount positions the shade in front of the recess, commonly on the wall or above the frame. It can cover more of the opening and may work better when the recess is shallow or the moving window sash needs clearance.

Neither mounting position automatically determines whether drilling is required. An inside-mounted shade may use screws; a no-drill product may use clamps, adhesive, or a compatible tension mechanism.

2. Inside Mount: When Does It Make Sense?

Inside mounting suits windows with sufficient recess depth, reasonably straight sides, and no handles or opening mechanisms obstructing the shade. The result is tidy and leaves the outside of the frame visible.

Before selecting it, check the depth at the actual fixing position, the width at multiple points, and the space needed for the shade headrail or housing. On inward-opening windows, also check how far the sash moves when tilted or opened.

The general Joydeco DE shade measuring guide lists 72 mm as a minimum recess depth for its standard inside-mount instructions. This is not a universal specification for every product or no-drill mounting system. Always verify the required depth and available mounting options on the specific product page before ordering.

3. Outside Mount: When Is It the Better Choice?

Outside mounting is worth considering when the recess is too shallow, the frame is uneven, or you want additional fabric coverage around the opening. It may also provide a way to mount the shade high enough to leave room for a tilt-and-turn sash.

Because the shade overlaps the opening, an outside mount can reduce side light gaps compared with a close-fitting inside mount, although the actual result depends on the product, fabric, hardware, and installation.

Check that the surface can support the selected brackets and that there is enough space for the shade to roll up or fold without obstructing the window.

4. How to Measure for an Inside Mount

First choose the intended installation position and use a metal tape measure. Record all values in millimetres to the nearest 1 mm; do not round them.

Measure the recess width at the top, middle, and bottom. Record the smallest width. Measure the height at the left, centre, and right. Record the largest height.

The general Joydeco DE shade guide describes a calculation of smallest recess width minus 3 mm, and uses the largest measured height as a reference; for zebra shades, the guide specifies the measured window height. These are reference rules from the general guide, not universal order-size instructions.

Important: These deductions apply only where the relevant product instructions confirm them. Certain no-drill tension-fit systems have their own sizing requirements. Do not deduct 3 mm automatically for a tension-fit shade.

5. How to Measure for an Outside Mount

Measure the outside width and height of the window frame, then decide exactly how much area the shade should cover.

The general Joydeco DE guide recommends adding at least 100 mm to the window width for extra coverage and privacy. For height, either add at least 150 mm to the frame height or measure from your intended upper installation point down to the desired end position.

Check the clearance above the frame, the position of nearby cabinets and radiators, and the space required by the selected mounting hardware. These measurements must match the instructions for the precise product.

Product availability matters: Not every Joydeco DE shade is offered with both mount types. For example, some no-drill Roman shades list inside and outside mount, while others specify no-drill inside mount only. Do not assume that a product advertised as “no-drill” also supports outside mounting. Select only the mounting type actually available for your chosen product.

6. What About Tilt-and-Turn Windows?

A tilt-and-turn window opens inward and can also tilt at the top. A shade fixed inside the recess may stay in place while the sash moves toward it. Even if the shade physically fits, the window may no longer open fully.

An outside mount above the opening can sometimes avoid that conflict, but only if the raised shade and its headrail clear the complete opening path. A clamp-on product attached to the moving sash is a different configuration; do not assume that a Joydeco DE recess-mounted no-drill shade uses sash-mounted clamps.

Before ordering, verify the sash opening path, the handle position, the headrail depth, and the available height above the window. If in doubt, provide the window measurements and photos for a product-specific compatibility check.

7. Common Measuring Mistakes

• Mixing up recess dimensions and order dimensions: The measured opening and the size entered into the product configurator are not always identical.
• Assuming every no-drill product uses the same deduction: Tension-fit, clamp-on, and conventional bracket systems can have different requirements.
• Ignoring window movement: Check full inward opening and tilt, not just whether the blind fits when the window is closed.
• Measuring only once: Recesses are not always perfectly square, so measure at multiple points.

8. Frequently Asked Questions

Is inside mount or outside mount better for privacy?

Outside mounting can offer additional overlap around the opening, which may reduce edge gaps. Fabric opacity and installation details still matter.

Can I use an inside mount on a tilt-and-turn window?

Only if the shade housing, mounting position, and window opening path are compatible. Confirm clearance before ordering.

Is an outside mount always a no-drill installation?

No. Inside/outside describes position; drilling depends on the actual attachment hardware.

Should I subtract 3 mm from every inside-mount order?

No. That is part of Joydeco DE’s general shade measurement guide, not a universal rule for all products, particularly tension-fit models.

9. Choose Your Mounting Position Before Ordering

If the recess has sufficient depth and clear opening space, an inside mount can deliver a clean, integrated appearance. If you need more coverage or the frame is shallow, an outside mount may be more suitable.

Start with the Joydeco DE Shade Measurement Guidelines, then check the available mount type, dimensions and installation instructions on your chosen product page. If the instructions do not clearly match your window, contact Joydeco DE customer service with measurements and photos before ordering a custom-made shade.