VELUX GCLSC082501H Heritage Conservation Roof Window (114 x 140 cm)

The VELUX GCL 2501H Heritage Conservation Roof Window (114 × 140 cm) is a bespoke solution for heritage, conservation, and historic properties. Blending timeless architectural character with modern performance, it’s specially designed in collaboration with conservation officers and architects to preserve the authenticity of older buildings while improving natural light, ventilation, and energy efficiency.

Key Features

Heritage Aesthetics

1. • Slim, black exterior profile: The window’s reduced external frame gives it a near-flush installation, allowing it to sit beautifully within slate or tile roofs and integrate subtly into traditional facades. 

   • Central glazing bar: A vertical glazing bar provides a classic, period-appropriate look, echoing cast-iron rooflights often found in historic buildings. 

   • Authentic winding handle: A hand-winder, fixed to the bottom frame, invokes a traditional style of operation and gives the window an old-world charm. 

     Glazing & Performance

      

     • Double glazing with premium features: The unit uses high-quality double-glazed glass with safety lamination, a toughened outer pane, easy-clean coating, a UV filter, and rain noise reduction technology for comfort, safety, and durability. 

     • Glass-to-edge design: This design maximizes natural daylight by minimizing the visible frame inside, giving a clean, elegant view. 

     • Thermal performance: The window has a U-value (thermal transmittance) of 1.3 W/m²·K, helping to maintain a warm and energy-efficient interior environment. 

     • Acoustic insulation: The glazing provides sound insulation (Rw ~ 35 dB) to reduce external noise, contributing to a quieter, more comfortable interior. 

     • Solar and light properties: Light transmittance (τv) is ~ 0.75, and the total solar energy transmittance (g-value) is ~ 0.56, striking a balance between letting in daylight and managing solar gain. 

        

       Operation & Ventilation

       • Top-hung design: Opens outwards from the top, allowing for a controlled opening of up to approximately 15 cm, which is ideal for natural ventilation without compromising safety or aesthetics. 

       • Manual winding handle: The traditional hand-winder mechanism is both authentic and functional, offering a tactile, heritage feel rather than modern motorised operation. 

        

        

2. Compatibility & Installation

   • Roof pitch suitability: Can be installed on roofs pitched between 20° and 65°. 

   • Flashing options: Compatible with VELUX flashing kits for plain tiles and slate (up to 14 mm), and there are flashing solutions (like EDV) for profiled tiles up to 90 mm, which simplifies fitting without bespoke lead flashings. 

   • Finish: Internal frame is finished in bright white-painted pine, giving a clean and crisp appearance that works well with modern interiors while preserving the traditional feel. 

3. Durability & Warranty

   • Robust construction: Made from high-quality pine wood and triple-coated for longevity, designed to withstand the demands of historic building refurbishment. VELUX

   • Guaranteed quality: Backed by a 10-year warranty, giving peace of mind for long-term performance. 

4. Regulatory & Safety Compliance

   • CE-marked: Conforms to relevant European standards for performance, safety, and durability. 

   • Fire & structural safety: External fire performance class is Broof(t4), impact resistance class 3, and air permeability class 4, ensuring the window meets stringent safety requirements.