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Key Selling Points

  • Fully bespoke sizes to suit your space and style, from 250 mm to 3000 mm with an impressive maximum of 2.25 medge-to-edge view of the skies above
  • Superior energy efficiency, achieving an astonishingly low thermal transmittance of Uw 1.1 W/(m2K), according to EN 14351-1 and with a 0.5 Ug value
  • All our rooflights come with a laminated inner glazing as standard, for superior safety in the unlikely case of breakage
  • Includes a 150 mm insulated wooden upstand


  • Our opening feature allows natural, healthy ventilation of your home, the mechanism is completely invisible as the motor is beautifully integrated into the upstand
  • The walk-on feature is available to you on all fixed square edged rooflights up to 2 m2
Customisation matters
You want your house to reflect your tastes, to incorporate a truly personal touch.
So do we.
Scandinavian design
Enjoy the sleek and simple touch of Scandinavian design that will give your house an effortlessly sophisticated vibe.
Lifelong assistance
We're proud of our heritage.
We're here to stay and more importantly, we're here for you.
True craftsmanship
75 years mastering and perfecting our art, finessing the science behind our rooflights and reach highest standards of quality.
10 years guarantee
We never promise more than we can deliver but we think it's always ok to deliver more than we promise.


Streamlined and sleek, The Long Slim One usually stretches across a wide span. It can be fully customised up to a ratio of 1:6, you might have a long window with a visible internal glass width of 500 mm and a length of 3000 mm. The maximum span for The Long Slim One is 3000 mm in either width or length and it can span up to 2,25 m2 of glazing, giving you a true "outdoors indoors" feeling from your rooflight.

To make your Long Slim One truly personalised, you can choose from a huge array of helpful features, such as:

  • Different insulating glazing units
  • Motorised ventilation
  • Walk-on capability for roof terraces
  • Other great custom features

The Long Slim One fits perfectly between rafters, and can span the length or width of the rafters, creating a magnificent band of light to pour daylight into your room from above. Need to go even bigger?

Try The Unlimited One where you can create your ideal span using a combination of units until you realise the full extent of your daylight desires.



Our insulated glazing units offer you the option of double glazing or triple glazing units for your rooflight. Choose double glazing for the maximum daylight drenching effect or triple glazing if superior energy saving eco credentials are your priority.

All our glazing units:

  • Come with a laminated inner pane, which we consider a prerequisite for safety measures 
  • Use three different glazing constructions to ensure the best quality and durability for our larger glazing units
  • Have warm edge spacers to ensure a thermal breakage and energy efficiency
  • Come with a 115 mm black silk screen to protect the underlying gasket system and for aesthetic purposes

As an example, our triple glazing has a LowE coating with a superior insulating value of Ug 0.5 and a light transmittance of 71%. We use an 8 mm toughened outer pane and a 12.76 mm (66.2) laminated inner pane, separated by two argon gas fillings for thermal performance. See all the specific values of our glazing constructions in our glazing table.

Frame Construction

Frame Construction

All our lightweight aluminium rooflight frames are:

  • Designed to work perfectly with our laminated insulating glazing units
  • Crafted from highly durable and strong 5 mm aluminium, selected for its high corrosion resistance, joint strength and malleability
  • Hand-welded on the inside of the corner sections to ensure a smooth surface and a completely seamless connection
  • Treated with a polyester powder coating to ensure a tough, weather and corrosion resistant, durable finish
  • Powder coated with our standard RAL 9005 Jet Black
  • Can be customised through a variety of special colours

We have constructed specific aluminium frames for our double glazing units and our triple glazing units, to ensure that the pane is positioned as low as possible in the construction, which ensures an ultimate insulating value for the rooflight.



The Long Slim One comes with a wooden upstand that uses rock wool insulation to keep your home snug. The natural wood allows for an easy and safe installation and is a perfect match to the remaining rooflight construction.

Our upstands come with:

  • A superior pre-fitted gasket system, ensuring a 100% tight and secure connection between the frame and upstand construction
  • A pre-installed vapour barrier, which ensures a safe and easy connection to the roof itself
  • An internal surface treated with a membrane of water based white coating (RAL 9010) on the waterproof plywood
  • An external surface of untreated waterproof plywood, which is great for applying roofing felt or other flat roofing materials

Our upstands come in 150 mm and 300 mm, depending on project requirements and architectural specifications.

For customised upstand heights, please contact us.



As all Vario by VELUX rooflights are bespoke products and individually made to order, the Declaration of Performance [DoP] will be unique for each roof window. Some of the essential characteristics will be based on product type, size and variant you choose for your long window. The specific DoP will be generated through our online DoP configurator, for each individual product.

If you would like to request a specific DoP, please contact us.



In our opening rooflights, the chain actuator is fully integrated in the wooden upstand. The actuator is not visible from the inside when the roof window is closed, thus there is no visual difference between fixed and opening rooflights.

A module with motorised ventilation is operated by either one or two actuators, depending on the clear internal area and the width of the window:

  • A double glazing rooflight needs two actuators if the product is larger than 2 m2 or has a width wider than 2000 mm
  • A triple glazing rooflights needs two actuators for a product which is larger that 1.5 m2 or has a width wider than 2000 mm

The Tech Stuff:

  • The actuator uses 3 amp and must be controlled by a separate OS ± 24V system
  • In the OS ± 24 V, the actuators are controlled by ± 24 V DC 
  • For the OS ± 24V, the actuators, control units and switches are supplied by Vario by VELUX
  • For two actuators, there will be a need for a larger control unit, which will be supplied by Vario by VELUX
  • The actuator can be integrated in common building automation fieldbus systems, e.g. KNX, BACnet, LON and Modbus, through the integrated MotorLink™ technology. Connection to a fieldbus system requires a separate control box between fieldbus system and actuator
Get your own
bespoke rooflight
Call us +44 (0) 1592 778 246 or email us vario@velux.co.uk
We're here to support you with your rooflight design and purchase in any way we can. All you have to do is ask our daylight experts!
We can help you design your dream home, using natural light from bespoke rooflights.
Daylight Design
Share your ideas and get help from someone who shares your passion for beautiful design.
Inspiration insights
Ask us about inspirational notes and insights that will serve as a stimulus to create your perfect daylight oasis.
Product Counselling
If you're not sure which Vario by VELUX rooflight you need, we can guide you to your perfect match.
Installation Guidance
Get support and guidance to help your rooflight installation be smooth and stress free.
Long Slim One Product Documentation
Installation Guide
Installation Guide for the fixed Long Slim One
Cross Section - Fixed Rooflight
Upstand 150 mm (PDF)
Cross Section - Fixed Rooflight
Upstand 300 mm (PDF)
Cross Section - Fixed Rooflight
Upstand 150 and 300 mm (DWG)
Cross Section - Opening Rooflight
Upstand 150 mm (PDF)
Cross Section - Opening Rooflight
Upstand 300 mm (PDF)
Cross Section - Opening Rooflight
Upstand 150 and 300 mm (DWG)