How to Install Blinds Outside Window Frame: A How-To Guide

Installing blinds may seem complicated, but it’s actually a very simple process that can be successfully completed by most beginners. Whether you’re looking to save some cash or just love completing DIY projects around the house, installing blinds outside a window frame is an easy home improvement you can do in one weekend. Below, we explain the difference between outside mounting and inside mounting blinds, and then we walk you through how to install blinds outside a window frame.

Outside Mount vs. Inside Mount

Outside mounting refers to positioning the blinds outside the window recess. Outside mounting can be used on all window types, regardless of how deep or shallow they are. Outside mount blinds result in less light leakage because you can get blinds that are wider than the window glass, providing more coverage, which can affect the impact of window blinds on daylight-linked dimming. 

Outside mount blinds can give the illusion of bigger windows, and they also give you the option to mount the blinds higher than the window, so they don’t cover any of the glass when they are open.

Inside mount blinds are installed inside the window recess. Because they lie flush with the wall, they are a good choice when you want to hang curtains or additional window treatments in front of the blinds. However, not all windows are deep enough to support an inside mount, so you must measure carefully before ordering to ensure your windows can indeed support inside mount blinds. 

The measurements must also be very precise; you can’t inside mount blinds that are too wide, so you might need to look into custom blinds if your windows are a non-standard size. (If you’re not sure how, check out our guide that explains how to measure for blinds.)

In some cases, you might want to install one set of blinds outside the window frame and one set of blinds inside. For example, if you layered a blackout roller shade with a roman shade, you would inside mount the roller shade and outside mount the roman shade.

How to Install Blinds Outside Window Frame

Installing blinds is a very easy process, especially if you are outside mounting them. Your blinds should already come with all the hardware you need to install them, though you will also want some basic tools (drill, tape measure, pencil, level) on hand as well.

• Unpack the blinds carefully and lay everything out before installation. Check to make sure you have all the hardware necessary, and carefully review the instructions to see if your blinds have any special considerations.

• Hold up the blinds in front of the window and decide where you want to mount them. Make sure not to put them too high or the blinds might not cover the bottom of the window when fully extended. Once you have decided on your final placement, double check the blinds are straight using a leveler. Mark the outside corners gently with a pencil and set the blinds down.

• Take the brackets and line them up with the pencil marks you made in the previous steps. Drill or screw the brackets into the wall or window trim using the included hardware.

• If your blinds came with a center bracket, you will also need to install that. Despite the name, center brackets usually need to be placed slightly off-center so as not to interfere with the center cord of the blinds. Measure the top of the blinds and decide where you will place the center bracket. Position the bracket using the level to keep it straight, and gently mark the placement with a pencil. Screw or drill the center bracket in place.

• Attach the valance clips to the front of the wooden blinds before mounting them. Make sure the clips do not interfere with any mechanisms at the top.

• Set the headrail into the brackets. Close the end brackets and make sure they have snapped securely in place.

• Finish assembling the valance by attaching the small side pieces to the main front piece. Snap the valance into the clips; first the top, and then the bottom. The valance will cover up the headrail and give your blinds a more finished look.

• If desired, you can open and close the blinds to double check the blinds are secure. Enjoy your new window treatments!

If you’re looking to get into DIY home projects, installing new blinds is an easy way to start. The process involves only a few tools, and you can install all the blinds in a room in just a couple of hours. Follow these steps to install blinds outside a window frame.