IT Duo Combi

Two windows next to each other, 100-160mm frame distance

The Duo Combi Installation Type is the classic way to combine two VELUX roof windows in a pitched roof.


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 Duo Combi?

Choose Duo Combi when you want to create a larger daylight opening while working with the existing roof construction.

In this installation type, the roof windows are installed on either side of a structural roof rafter, which remains between the windows and is typically finished on the interior side with plasterboard or a similar lining solution.

Duo Combi is a well-established and widely used installation principle. It provides a practical and flexible way to increase daylight, views, and ventilation while maintaining the structural logic of the roof construction.

The flexible gutter between the windows allows a frame distance of 100–160 mm, making the solution adaptable to a wide range of common rafter dimensions and pitched roof constructions.

Key Benefits

- Wider daylight opening than a single roof window
- Designed to work with the existing roof construction
- Existing structural rafter retained between the windows
- Flexible 100–160 mm frame distance between windows
- Practical and well-established installation principle
- 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