VELUX CFU & ISU Fixed Flat Roof Rooflight
The VELUX CFU & ISU Fixed Flat Roof Rooflight is a beautifully designed glazing solution that transforms flat roof spaces by bringing in an abundance of natural daylight. Perfect for brightening living areas, extensions, offices, or commercial spaces, this rooflight delivers a clean, modern look with exceptional energy efficiency and long-lasting performance.
The CFU base unit combined with the ISU fixed flat glass top unit creates a sleek and minimalist appearance, both inside and out. The frameless internal design allows uninterrupted views of the sky, while the flat, toughened glass exterior ensures a stylish, low-profile finish that blends seamlessly with any modern roofline.
Engineered for durability and thermal performance, the VELUX CFU & ISU system features high-quality double or triple glazing options to reduce heat loss and minimize external noise. The innovative design also prevents condensation build-up and ensures excellent drainage — keeping your rooflight crystal clear and functional all year round.
With its easy installation and premium materials, this fixed flat roof window is the perfect combination of aesthetic appeal, energy efficiency, and reliability — a hallmark of VELUX craftsmanship.
Key Benefits
• Maximum daylight: Fixed flat glass design allows light to flood interior spaces.
• Sleek appearance: Frameless interior and low-profile exterior for a modern finish.
• Energy efficient: Double or triple glazing reduces heat loss and improves comfort.
• Weather resistant: Toughened glass and superior seals ensure long-term durability.
• Low maintenance: Designed to resist condensation and easy to keep clean.
• VELUX reliability: Backed by years of trusted engineering and design expertise.
Typical Applications
• Flat roofs on residential or commercial properties
• Kitchen extensions and living room spaces
• Offices, stairwells, and hallways requiring more natural light
• Renovations or new build projects needing a modern rooflight solution
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Specifications
• Product Name: VELUX CFU & ISU Fixed Flat Roof Rooflight
• Type: Fixed (non-opening) flat roof window
• Base Unit: CFU (composite base frame)
• Glazing Unit: ISU (flat glass top)
• Glazing Options: Double or triple glazing available
• Operation: Fixed (no ventilation)
• Frame Material: Maintenance-free PVC
• Glass Type: Toughened outer glass, laminated inner pane
FAQs
Is the VELUX CFU & ISU Rooflight suitable for all flat roof types?
Yes. It is compatible with most flat roof materials, including single-ply membranes, bitumen, and GRP systems. Always ensure the installation is carried out according to VELUX guidelines for best results.
Can the rooflight be opened for ventilation?
No. This version is a fixed unit, meaning it does not open. If you require ventilation, VELUX also offers opening versions such as the **VELUX CVU** model.
Does the rooflight provide good insulation and noise reduction?
Yes. The CFU & ISU system is designed with high-performance double or triple glazing to deliver excellent thermal insulation and significantly reduce external noise.
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