Inside Mount vs Outside Mount Blinds: Which is Better?

Introduction

Before you choose the style or colour of your blinds, there's a basic decision to make: inside mount or outside mount? This choice affects how your blinds look, how they perform, and how you measure for them.

It's one of the most common questions we get at Blinds Planet, and the answer isn't always the same. Here's a guide to help you pick the right mounting method for every window in your home.

What is inside mount?

Inside mount means the blind is installed within the window frame, fitting snugly inside the window opening.

The blind sits:

Visual effect

Inside mount creates a clean, built-in appearance. The window trim stays visible, framing the blind neatly. It's the go-to choice for modern and minimalist interiors.

What is outside mount?

Outside mount means the blind is installed on the wall or trim above and beyond the window frame, covering the entire window opening and extending past it.

The blind sits:

Visual effect

Outside mount makes windows appear larger than they are. The blind hides the frame entirely, which is great for a full-coverage look.

Side-by-side comparison

When to choose inside mount

1. Attractive window trim

If your home has beautiful crown moulding, craftsman-style casings, or heritage trim around the windows, inside mount shows it off. Many older GTA homes, particularly in established Toronto neighbourhoods, have original wood trim that adds character to the room.

2. Modern and minimalist interiors

Inside mount fits with contemporary design. The blind becomes part of the window rather than something added on top of it. For clean-lined GTA condos and modern new builds, this is the standard approach.

3. Sufficient window depth

Inside mount needs enough recess for the product you've chosen. The shallowest fit is a roller on slim brackets, which squeezes into 30 mm of depth; a standard roller bracket or a cellular shade wants 40 mm. A zebra cassette is a little deeper at 50 mm. Wood and faux wood slats, and any roller or zebra carrying a motor tube, need 65 mm of clear recess, while verticals ask for the most at 75 mm.

Measure from the front of the window frame to the glass. If your recess meets the minimum for your product, inside mount is an option.

4. Multiple windows close together

When windows are grouped closely or share a continuous frame, inside mounting each blind individually creates a tidy, organized look. Each blind operates independently without overlapping its neighbour.

5. Clean sightlines

For windows where you want the blind to "disappear" when raised, inside mount with a compact headrail keeps the hardware hidden within the recess.

When to choose outside mount

1. Shallow window recesses

If your window recess is too shallow for inside mount (common in older Brampton and Scarborough homes, and in many condo buildings), outside mount is your only option. No problem; it looks great with proper sizing.

2. Maximum light blocking

For blackout applications, outside mount is superior. By overlapping the window frame by 3-4 inches on each side and 3 inches above, you eliminate the light gaps that are inherent in inside mount.

Best for:

3. Making small windows look larger

Outside mount is an interior designer's tool for visual window expansion. By extending the blind 4-6 inches beyond the frame on each side and mounting 6 inches above, a standard 36-inch window appears much wider and taller.

This trick is especially useful in:

4. Covering unattractive frames or walls

If your window trim is damaged, mismatched, or unattractive, outside mount blinds hide it entirely. This is a cheaper alternative to replacing trim.

5. Window obstructions

Crank handles, window locks, sensors, or other hardware inside the recess can interfere with inside-mount blinds. Outside mount clears these obstructions entirely.

6. Better insulation

Outside-mount blinds that overlap the frame create a more complete barrier between the window and the room. For energy efficiency, especially during Ontario winters, this sealed coverage reduces drafts and heat loss more effectively than inside mount.

How to measure for inside mount

Precision matters for inside mount. A blind that's too wide won't fit; too narrow leaves visible gaps.

Step by step:

Width:

1. Measure the inside width of the window opening at three points: top, middle, and bottom.

2. Record the narrowest measurement.

3. Measure to the nearest 1/8 inch.

4. Do NOT add any deductions. Blinds Planet will apply the factory deductions (typically 1/4 inch to 3/8 inch) during manufacturing.

Height:

1. Measure the inside height at three points: left, centre, and right.

2. Record the longest measurement.

3. Measure from the top of the opening to the sill.

Common mistakes:

How to measure for outside mount

Outside mount is more forgiving, but good measurement still matters.

Step by step:

Width:

1. Measure the width of the window opening (frame to frame).

2. Add 3-4 inches on each side (6-8 inches total) for light blocking coverage.

3. For purely aesthetic coverage, add 2 inches on each side.

Height:

1. Decide how high above the window you want to mount (typically 3-6 inches above the frame).

2. Measure from your desired mount point down to the sill or below.

3. For a floating look, stop at the sill. For full coverage, extend 1-2 inches below.

Mounting Surface:

Ensure the wall above your window is solid enough for mounting hardware. If there's a header (structural beam above the window), mark its location. If mounting into drywall only, use appropriate anchors rated for your blind's weight.

Room-by-room recommendations

Living room

Recommendation: Inside mount if your recesses allow it. Clean sightlines let your furniture and decor take centre stage.

Bedroom

Outside mount for maximum blackout. The overlap eliminates light leaks that inside mount can't avoid.

Kitchen

Inside mount. Keeps the blind recessed and away from splashes, steam, and cooking activity.

Bathroom

Inside mount for privacy (the blind sits within the recess, closer to the glass) or outside mount for small windows you want to visually enlarge.

Home office

Inside mount for zebra blinds. Clean look that doesn't distract from your workspace.

Condo floor-to-ceiling windows

Inside mount where recess depth allows, outside mount otherwise. For ceiling-track-mounted blinds, this is technically a ceiling mount (a variation of outside mount).

Can you mix mount types?

Absolutely. Many GTA homes use a combination:

Consistency matters within a room, but different rooms can use different mounting methods without looking disjointed.

Professional measurement matters

While DIY measurement is doable, professional measurement eliminates costly errors. Our free measurement service includes:

One mismeasurement on inside-mount blinds means a blind that doesn't fit, requiring re-ordering and waiting for replacement.

Why choose Blinds Planet?

Contact us at (416) 890-4554 or request a free quote. We'll measure, recommend, and install so your blinds look and perform the way they should.