Double-walled plastic skylights are unsuitable for heated spaces and provide little to no insulation.
These cannot be compared to double glazing! Only use them for unheated spaces such as carports, garages or factory halls. Triple-walled skylights are suitable for hallways and storage rooms, but not for living areas such as living rooms, kitchens or bathrooms. Choose four- or five-walled skylights in heated homes. A four-walled skylight meets the Belgian EPB standards. With a five-walled skyligh, you can request insulation premiums . Combine the skylight with a well-insulating curb.
Type |
Product |
EPB compliant |
Suited for passive houses |
Insulation premium |
Suited for which space |
Flat roof window (glass) |
iWindow2 |
✓ |
|
✓ |
Heated spaces |
Flat roof window (glass) |
iWindow3 |
✓ |
✓ |
✓ |
Heated spaces, passive houses |
Hybrid |
iDome |
✓ |
|
✓ (with 5-walled skylight dome) |
Heated spaces |
Plastic skylight |
Single- and double-walled |
|
|
|
Unheated spaces (carports, garages, factory halls) |
Plastic skylight |
Triple-walled |
|
|
|
Corridors, storage rooms (not living areas) |
Plastic skylight |
Four-walled |
✓ |
|
|
Heated spaces |
Plastic skylight |
Five-walled |
✓ |
|
✓ |
Heated spaces |