Flat Roof Skylight 400 x 400 mm, Frameless Triple Glazed, 10.20kg, UV 0.9
Original price was: £ 274.00.£ 175.26Current price is: £ 175.26. incl. VAT
Prices go up when the timer hits zero.
3 in stock (can be backordered)
Skylights.co.uk: Trusted rooflights. Built to prevent leaks.
Type: Fixed Frameless Flat Roof Skylight
Internal Size: 400 x 400 mm
External Size: 600 x 600 mm
Glazing Type: Triple Glazed
Net Weight: 10.2kg
U Value: 0.9 W/m²K
G Value: 58%
Light transmittance : τv [%] 72
Sound reduction (EN 12758): 39dB
UV transmission : τuv [%] 0
Toughened safety & laminated glass
Leakproof Design
Our Flat Roof Skylights are composed of three distinct glass panes, each contributing to the unit’s durability and thermal efficiency:
- Top Pane: 6 mm Planibel Clearlite / Thermally toughened glass, compliant with BS EN 12150
- Middle Pane: 4 mm Planibel Clearlite / Thermally toughened glass, compliant with BS EN 12150
- Bottom Pane: Stratobel Clearlite 44.2 iplus 1.1 / Laminated glass with Low-E coating, compliant with EN 14449
Premium Flat Roof Skylights
Are you thinking of adding a skylight but worried about heat loss? Our Flat Roof Skylight, measuring 400 x 400 mm, boasts an impressive U-value of 0.9 W/m²K, thanks to its triple-glazed units and warm edge spacer technology. This means superior insulation, keeping your space cosy in winter and pleasantly cool in summer while enjoying abundant natural light!
Why Choose Our Frameless Flat Roof Windows
- Energy Efficiency: Triple-glazed units and warm edge spacer technology offer outstanding thermal performance. With a U-value of 0.9 W/m²K, your space remains comfortable year-round, reducing energy bills.
- Unobstructed Views: The frameless design maximizes natural light, offering breathtaking panoramic sky views.
- Self-Cleaning Convenience: Maintenance is effortless with a sunlight-activated self-cleaning feature that keeps the glass spotless.
- Versatile Installation: It is suitable for flat roofs with pitches between 6° and 45°, making it an excellent fit for many homes.
- Peaceful Ambiance: Provides effective soundproofing for a quieter indoor environment.
- Sun Safety: Offers protection against harmful UV rays.
- Safety First: Constructed with safety-toughened glass for ultimate peace of mind.
- Regulation Compliant: Meets all British Standards & Building Regulations and carries the CE safety marking.
Essential Skylight Accessories
Enhance your flat roof skylight experience with these essential add-ons for a seamless skylight installation and optimal performance:
- Installation Kit for 1 x Flat Roof Skylight 400x400mm: This complete kit provides everything needed for a secure and stress-free installation, ensuring optimal performance and lasting enjoyment of your skylight.
- Foam Rope – Structural Glazing Tape – 9mm Thick (7.5m Rolls): This high-quality tape offers effective sealing and crucial support during installation for a secure fit.
- Weatherproofing Sealant (Silicon) – DOWSIL™ 791, 310ml: This durable sealant creates a watertight seal around your skylight, keeping the elements out and ensuring a comfortable indoor environment.
- Self-Cleaning Liquid Smart Glass Bottle 15ml: This special solution replenishes the skylight’s self-cleaning properties, ensuring effortless maintenance and sparkling glass with minimal effort.
Choose Skylights.co.uk
We offer a variety of standard sizes readily available for purchase, along with custom skylights to suit your specific needs.
No matter the project, our flat roof lights provide:
- Exceptional Thermal Performance: Enjoy outstanding energy efficiency thanks to innovative features like triple glazing, keeping your space comfortable year-round.
- Natural Light Abundance: Bathe your space in beautiful natural light with our skylights, creating a brighter and more inviting atmosphere.
- Elegant Design: Add a touch of sophistication to any setting with our sleek and modern flat roof lights.
Download our full product catalogue to explore our extensive Flat Roof skylight range and find the perfect solution for your project.
Ready to discuss your skylight needs? Contact us today!
🗺️ Where to Buy 400 x 400 mm Flat Roof Skylights Near Me
Looking for a 400 x 400 mm flat skylight near you? Also known as a 0.4 x 0.4 m roof light, this size is a great fit for compact spaces where natural light can make a big difference—like utility rooms, landings, or en-suite bathrooms. We build high-performance flat roof lights that combine clean, modern design with lasting durability.
✅ 20-Year Warranty Included
✅ Installer Support Available
✅ Rated 5 Stars on Google
✅ Secure Checkout & Payment Options
✅ Custom Sizes Available
Every skylight is UKCA-certified, weather-tested, and manufactured to meet strict quality standards. We offer fast nationwide delivery, so wherever you are, you can count on us for reliable, professional-grade roof lights that brighten your project and stand the test of time.
| Weight | 10.2 kg |
|---|---|
| Dimensions | 65.0 × 10.0 × 65.0 cm |
| Internal Size |
400 x 400 mm |
| External Size |
600 x 600 mm |
| Glazing Type | |
| Glass Tint | |
| Self-Cleaning: |
Yes |
| Roof Type |
Flat Roof ,Pitched Roof |
| Skylight Type |
Frameless |
| Top Glass Pane: |
6 mm Planibel Clearlite / Thermally toughened glass EN 12150 |
| Air Gap |
16 mm Argon 90% |
| Middle Glass Pane: |
4 mm Planibel Clearlite / Thermally toughened glass |
| Air Gap |
16 mm Argon 90% |
| Bottom Glass Pane: |
Stratobel Clearlite 44.2 iplus 1.1 pos.5 / Laminated glass with Low-E coating EN 14449 |
| Spacer Type |
15mm Black Warm Edge |
| U value |
0.9 [W/(m².K)] |
| Sound reduction - EN 12758 |
[dB] 39 (-2;-7) |
| Light transmittance: tv [%] |
72 |
| External light refection : ρv [%] |
17 |
| Internal light refection : ρvi [%] |
17 |
| Colour rendering index : Ra [%] |
97 |
| Solar energy transmittance : g [%] |
57 |
| Shading coefcient : SC |
0.66 |
| Selectivity |
1.26 |
| UV transmission : τuv [%] |
0 |
Sold By Manufacturer
3 in stock (can be backordered)
16 in stock (can be backordered)
ACTIVE PROMOTION
Use Code: TODAYONLY
Transform your home with our triple-glazed flat roof skylights, maximizing natural light and thermal efficiency. Pair them with our separately sold Insulated Upstand, featuring 40mm core insulation to cut heat loss and lower energy costs.
Why Choose Our Insulated OSB Upstands?
Perfect Pitch for Water Drainage
Built-In 6° Pitch for perfect drainage
Exceptional Insulation
High Insulation with 40mm core and 15mm OSB
Ready-to-Install, Precision-Cut Fit
Factory-made to match our skylights exactly
Brighten Your Home & Save More – Bundle & Save!
Upgrade with our triple-glazed flat roof skylights for maximum light and energy efficiency.
Add the Insulated Upstand and save up to 7% with our bundle offer!
✔️ Boost thermal performance
✔️ Cut energy costs
✔️ Enjoy lasting durability
Get the complete solution at a better price – bundle today!
Get a Bundle with extra 7% Discount on Skylight and Upstand
Flat Roof Skylight 400 x 400 mm, Frameless Triple Glazed, 10.20kg, UV 0.9
Original price was: £ 274.00.£ 162.99Current price is: £ 162.99. incl. VAT
Inclined Insulated Upstand for Flat Roof Skylight 400 x 400 mm
Original price was: £ 108.00.£ 80.35Current price is: £ 80.35. incl. VAT
Before and After
See how a space is completely transformed with a Skylights.co.uk.
- Maximum daylight
- Modern minimalist design
- Superior insulation & UV protection
One change. Total transformation.
Our Roof Windows in Action
Photos from completed projects by our clients
Quick Shipping
Get it fast with our expedited shipping options.
Secure Payment
Shop safely with our secure online checkout.
Easy Returns
Hassle-free returns within 30 days.
20 Year Warranty
Enjoy peace of mind with our extensive warranty.
TILE & MEMBRANE COMPATIBLE
FLAT ROOFS
EASY & SECURE INSTALLATION
Will It Fit My Roof?
1. Flat Roofs
Our skylights are suitable for flat roofs with a minimum pitch of 6° when installed with the correct upstand or flashing kit.
2. Tile & Membrane Compatible
Designed for all common UK roof types – from clay tiles and slate to EPDM, GRP, and bitumen flat roof membranes.
3. Easy & Secure Installation
Each skylight is engineered for watertight, airtight installation. Use our installation kits and add our pre-fabricated upstands for a perfect fit and finish.
FAQ
Our triple-glazed models offer U-values as low as 0.9 W/m²K (whole unit), helping you meet Part L regulations and reduce heat loss.
Yes. All our skylights come with self-cleaning glass as standard to reduce dirt buildup.
Yes. We offer made-to-measure rooflights to fit your exact requirements. Contact us for a custom quote.
Yes. When installed with our official flashing kit and according to instructions, it is guaranteed to be watertight.
Absolutely. Each unit uses toughened outer and laminated inner glass that complies with UK safety standards (EN12150 / EN14449).
We offer a 20-year guarantee on the glazing unit.
Isabella Evans –
We chose a 400 x 400 mm skylight for our small bathroom, and it’s our best decision. The natural light it lets in makes the space feel so much larger and more welcoming. Regal Glass Group’s quality is superb!
Daniel Fisher –
The skylight was easy to install.
Peter Armstrong –
Bought a skylight for my client’s kitchen. Good quality and easy to install.
James Brooks –
Happy with the skylight in our kitchen. It’s bright and functional.
Sarah McAllister –
Living in Liverpool, we love how the flat roof skylight has brought natural light into our kitchen. It’s well-made and really enhances the space.
Cameron Fraser –
The flat roof skylight has made such a difference in our Manchester home. It brings in so much light and looks great in our modern extension.
Thomas Webb –
We’re really impressed with the quality of the skylight. It makes the entire room feel brighter and more spacious. Quick delivery and great technical support!