IT Side-by-Side Twin

Two windows next to each other, 18mm frame distance, no middle rafter, VELUX trimmers type EMT on top and at the bottom.

The Side-by-Side Twin installation type transforms two individual roof windows into a coordinated daylight solution that is easier to specify, visualize, and install.


Installation type - Object Type Description

Speed up your early design process with pre-defined VELUX installation solutions.

Use Installation Types to quickly explore daylight concepts, roof layouts, window sizes, and roof window placements without committing to detailed product specifications too early in the project.

These lightweight BIM objects are specifically developed for concept and schematic design stages. Geometry and product information are intentionally simplified, allowing you to focus on space, daylight, proportions, and overall design intent while maintaining maximum flexibility for later project development.

Switch between different roof window sizes and configurations to identify the solution that best fits your design. Once the project requirements become clearer, refine the selected Installation Type into specific VELUX roof windows with detailed performance data, operation type, glazing, finishes, blinds, shutters, and accessories.

When your project requires detailed geometry and specification-ready product information, continue the design process using CoBIM and the VELUX Revit Add-in.

Why choose Side-by-Side Twin?

While several VELUX solutions allow two roof windows to be placed next to each other, Side-by-Side Twin is specifically designed to create the most integrated appearance and maximize the usable space beneath the windows.

The key differentiator is the exceptionally small frame distance of only 18 mm. From both inside and outside the building, the windows appear almost as a single glazed opening separated only by a slim mullion.

Unlike conventional twin-window installations, no central rafter extends below the window line. Special EMT trimmers transfer the structural loads above and below the opening, creating a cleaner interior finish and preserving valuable headroom and room volume.

The integrated installation package combines flashing, EMT trimmers, insulation frame, underfelt collar, and cover plate into a coordinated solution that simplifies installation and helps achieve a durable, weather-tight result.

Key Benefits

- Wider daylight opening than a single roof window
- Minimal 18 mm frame distance between windows
- Valuable headroom and room volume
- No visible central rafter below the glazing
- Enhanced views and stronger connection to the outdoors
- Increased natural ventilation potential
- Factory-engineered installation system
- Faster and simpler installation process
- Consistent detailing and weather performance