Before You Cut: 6 Things to Know About Installing EX UP Windows

The right windows can completely transform a van conversion or expedition build. They bring in natural light, improve ventilation, and help make the interior feel like a true living space.

But not all windows perform the same.

EX UP windows feature lightweight, double-pane acrylic construction that delivers excellent thermal performance, impact resistance, and flexural strength. They cost more than some alternatives, but their durability and all-season performance make them a worthwhile investment.

At Expedition Upfitter, we have tested multiple window systems in our Total Composites expedition boxes. We keep coming back to EX UP windows.

That said, a great window still needs the right installation. Before you place an order—or cut a hole in your vehicle—work through these six essential considerations.

1. Protect the Van’s Major Support Structures

Before reaching for the saw, know exactly what is behind the sheet metal.

Most utility vans have recessed panels intended for windows or cargo doors. These areas may contain lightweight supports that keep the exterior skin rigid, while heavier structural members surround the panel.

Minor supports can sometimes be modified, but major supports should never be cut or altered.

For installations in curved van walls, we recommend leaving at least 3 inches of unobstructed sheet metal on each side of the window. If the wall has only a slight curve—approximately 1/16 inch across the opening—less clearance may be acceptable.

The 450 × 500 mm window in the passenger-side rear door of a Ford Transit is a good example. It is a tight fit, but installers have completed it successfully many times.

Most clearance issues occur along the vertical sides. If the wall is flat along the top and bottom, 1½ inches of free sheet metal may be enough. You will still need approximately 2 inches of clearance from nearby supports so the blind and screen assembly can operate properly.

Why does this space matter? It gives the sheet metal room to flatten against the window frame. Without enough clearance, the wall may force the window to follow the vehicle’s curve, creating unnecessary stress and making it harder to achieve a reliable seal.

Watch for angled corners, too. They can quickly reduce the usable installation area—especially in the sliding-door panels of many Sprinter vans.

2. Plan for More Than the Window Opening

The window might fit perfectly while the blind assembly does not.

The integrated blind and screen assembly is slightly larger than the window. That extra size allows both components to open fully, but it also means you need to plan around cabinets, countertops, shelves, and wall panels.

Leave at least ½ inch of open space above and below the assembly. You will need that room to open the housing and reach the mounting screws during installation.

Before ordering, map out the complete interior—not just the window cutout. A few minutes of careful planning can prevent a frustrating conflict later.

3. Give the Blind and Screen a Solid Mounting Surface

The blind and screen assembly hooks onto the window and screws into the finished interior wall. That means it needs solid framing beyond the window opening.

Extend the frame at least 1 inch past the cutout and provide a secure mounting point at each corner. Without adequate framing, the blind assembly may flex, loosen, or become difficult to operate.

Some builders prefer to install the window through the finished wall and mount the blind and screen separately. That approach works, too. The assembly does not have to attach directly to the window—as long as it is properly aligned and securely mounted.

4. Stop Panel Vibration Before It Starts

Some van panels are notorious for vibration. The angled rear sections of Sprinter vans are a common trouble spot.

An unfinished panel can behave like a drumhead, flexing and vibrating as the vehicle moves. When a window is mounted in that area, the movement may produce rattling—even when the window itself is installed correctly.

The solution is a properly finished wall. Add insulation and a rigid interior panel that ties into the outer skin. This reinforces the wall, controls vibration, and creates a more stable foundation for the window.

It is a smart practice for every installation, not just known problem areas.

5. Get the Wall Thickness Right

Wall thickness is not a minor detail. It determines which trim ring you need and whether the window can clamp securely into place.

EX UP windows are available with these popular trim-ring ranges:

• 24–34 mm
• 45–54 mm
• Also available 35-44 and 65-74mm (please reach out to customer service if you requite this thickness and we will do our best to accommodate)

The minimum wall thickness is 24 mm, or approximately 15/16 inch. If your finished wall is thinner, you will need to fabricate a spacer frame. Every sheet-metal van installation requires enough framing to meet this minimum thickness and create a flat, stable mounting surface.

Hardwood and metal tubing both work well. Install the spacer inside the van before fitting the window.

You can secure it with a high-strength polyurethane adhesive or very-high-bond tape. Clamp the spacer firmly against the sheet metal while installing it. This helps pull the curved exterior panel flat so the window can clamp evenly and seal correctly.

The frame does not need to be complicated. Four carefully fitted pieces of hardwood or aluminum are often all you need.

6. A Window Is Not a Roof Hatch

This one is simple: do not install an EX UP window in the roof.

EX UP windows are designed for appropriate vertical wall installations. They are not engineered, tested, or approved for use as roof hatches.

If you need roof access or overhead ventilation, choose a product specifically designed for that purpose.

Measure Twice. Then Measure Again.

Installing a window is one of the most exciting moments in a build—but it is not a job to rush.

Confirm the dimensions. Check the structural supports. Measure the finished wall thickness. Verify the interior clearance. Make sure the blind and screen can operate without hitting cabinets or countertops.

Then check everything one more time before ordering or cutting.

Returning EX UP windows can be difficult and expensive, and a misplaced opening in the side of a van is even harder to correct. Careful planning now can save hours of frustration later.

For more information download all the spec's, dimensions, installation guide and manuals here!