Xtralite and Vitral are now a part of VELUX Commercial, and we are delighted to welcome you to our new website. Here, you will find our complete portfolio of daylight solutions and services for industrial, commercial and public buildings.

Size Options for Modular Rooflights

Check out the size overview of prefabricated Modular Rooflights, which come in three variants: Monolight, Linearlight and Circularlight.

How to measure the modules 

The clear internal measure is determined by the interior dimensions of the 90° lining or lining profile of the product: A (Length – slope direction) and B (Width)

Clear Internal
A = Clear internal module length
B = Clear internal module width


Modular Rooflights Monolight longitudinal section B

Monolight Burglary-resistant

Clear internal measurement of Monolight Burglary-resistant


Modular Rooflights Monolight and Linearlight cross-section bottom A

Monolight/Linearlight Burglary-resistant

Clear Internal Measurement Monolight/Linearlight Burglary-resistant


Modular Rooflights Linearlight longitudinal section B

Linearlight Burglary-resistant

The clear internal measure of the product lining for Linearlight Burglary-resistant
There are different size options for Monolight, Linearlight and Circularlight, and you need to consider the following when choosing the correct size overview:

Monolight – Made-to-measure

Monolight – Made-to-measure size grid
Symbol explanation
Monolight size grid explanations

Linearlight – Made-to-measure

LInearlight – Made-to-measure size grid
Symbol explanation
Linearlight size grid explanations

Circularlight – Made-to-measure

Ø between 900 and 1350 mm depending on module type
Circularlight made to measure size overview
Symbol explanation
Circularlight size grid explanation

Roller blinds – Made-to-measure

Overview sizes Roller blinds
Symbol explanation
Roller blinds size grid explanations

Configuration options

Modular Rooflights product overview – features and limitations

* Depends on snow and wind load - a static calculation must be performed

Monolight and Linearlight are including burglary-resistant versions. Max. measurement of shortest side for these is 1600 mm.