# Add Roof Windows
To add a Roof Window or Clerestory Window, a few steps are required to be completed to ensure the window faces into a conditioned space.
## Add Roof/Clerestory Windows
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### Project the Roof to the Ceiling
Navigate to the drawing space and select the zone where you want to add the window. Left-click 'Using Envelope Settings' and navigate to the 'Ceiling' tab. Under 'Ceiling Method', choose 'Projected'. This will project the ceiling up to the roof level, combining the void above the ceiling with the space below to create one continuous volume. You now have a conditioned space where the roof or clerestory window can be added.
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### Edit Roof Geometry
Go back to Levels, then select 'Roof Geometry' and click 'Edit'. Select the aspect of the roof where you would like to place the window. Left-click on the desired face, then click 'Select Windows'.
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### Select Window Type
You will see two options for adding the window. As Concept, that define custom performance values and As Default, which use building default values or tags. In this case, select 'As Concept' and then the performance of the window (this can be changed later). We now have specifications provided for the roof or clerestory window.
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### Set Window Placement
Open the 'Window Placement' tab. Use the offset options to position the window. You can offset from the 'Left', 'Right', 'Top', 'Bottom', 'Top Roof Line' or 'Bottom Roof Line'. Use the sliders to adjust the placement, and remember, you can fine-tune the values using your keyboard arrow keys for precise adjustments.
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### Finalise and Review
Once you are happy with the placement, select 'Save and Close'. Switch to '3D View' and re-run the simulation to generate the updated DXF file.
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