The UK’s most secure, sustainable and stylish roof lantern

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Flood your home in light with our ultra secure, thermally efficient lanterns

Choosing the right roof lantern for your home is an important decision. They should let in the maximum amount of light, yet keep heat in your home and would be intruders out. Letting you enjoy more natural light and amazing night time views of the stars, while bringing a sense of space and tranquillity to your home. This is why we have designed the S1 aluminium roof lantern from the ground up to meet your every need. Building on years of experience, we’ve incorporated many new innovative ideas to create a warmer, slimmer and much more secure roof lantern. Thermlock® multi-chamber thermal technology helps keep heating bills low, while deep internal bars create an ultra strong structure for spans up to 3.2 x 6m without tie bars. Ultra low line aesthetics give a stylish architectural appearance, enhanced with hardwearing powder coated  aluminium inside and out. Security is also built into the heart of every S1 lantern, helping protect you and your home.

The UK’s most secure lantern,
keeps you and your home safews

The innovative construction of the S1 system eliminates the security weaknesses of traditional lantern designs. Features such as anti-tamper screws, enclosed anti-tamper glazing, security tape and our patent pending glass lock, alongside our unique high security ridge end, ensure there isn’t an easy way to enter your property via your flat roof lantern. All of these innovative features combine to make Sheerline’s S1 system the UK’s most secure aluminium lantern roof*.

A laminate glass upgrade is also available for extra security if required. So if you are looking for a lantern that comes with extra peace of mind as standard – then we have you covered.

*Mainstream residential roof lantern – not utilising bonded glass.

critical style bifolding doors
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Whatever the weather Thermlock® technology helps keep you comfortable and heating bills lower

The S1 lantern combines aluminium’s clean lines with exceptional thermal performance and features our innovative Thermlock® multi-chamber technology to keep you and your property well insulated against the worst of the UK weather. This coupled to high performance 28mm glazing means our lantern roofs offer class leading thermal performance, far superior to traditional polyamide systems based around 24mm glazing. A unique co-extruded perimeter seal also ensures draughts and rain are kept safely outside. 28mm glazing also allows acoustic dampening glass to be fitted if required.


28mm glazing 1.0 U-value W/(m²K)*

Thermal transmittance, also known as a U-value, measures the rate of transfer of heat. The better-insulated a window is, the lower the U-value will be.

*Centre pane U-value. Subject to glass specification.

critical style bifolding doors
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With great looks from every angle – due to our unique ultra low line aesthetics
With great looks from every angle – due to our unique ultra low line aesthetics

Slim, consistent 50mm rafter, hip and ridge sightlines maximise the light flooding into your home, creating bright, airy interiors and banishing gloom. The S1 lantern also features ultra low line aesthetics so rafter and hip top caps sit close to the glazing level on the exterior, creating a sleek modern look. Completing this refined architectural appearance our corner and rafter end caps run perfectly in line with the perimeter of the lantern, so no unsightly angles jut out to spoil the perfect lines of this outstandingly beautiful high-performance aluminium lantern. Leaving you with the ideal balance of understated refinement, contemporary looks and exacting quality standards.


With a wide range of styles and sizes to suit every project

Sheerline aluminium roof lanterns are available in a choice of 10 styles from square ‘pyramid’ designs to grander options suitable for larger ‘orangery’ style installations. Maximum sizes range from 2.4 up to an impressive 6m long, all set at a 25˚ pitch and all weather rated for the whole of the UK*.

*Rated for a snow load of 1.2 KN/m2. Covering the whole of the UK up to 200m altitude.

critical style bifolding doors


Sheerline lanterns are available in three standard powder coated colours, with the option of choosing a different colour for the interior to help you create the look that is perfect for your property. Bespoke colours can also be ordered to accent, or match your particular project requirements.

“Please note; due to the nature of the manufacturing process and the differences in the methods used to represent these colours on screen we cannot guarantee an exact colour match with the colours shown. The RAL colour references are also provided as a guide only.’‘


With a shared design philosophy, and built around the same ingenious and unique engineering principles, Sheerline’s aluminium systems are designed be used seamlessly together. So rest safe in the knowledge that aesthetics, colours, styles and sightlines will match perfectly across your home.


Find Out More

Please contact us for more information about the S1 lantern roof or any other Sheerline product, and to be put in touch with your closest Sheerline installer.

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At Roof Lanterns Online, we know what kind of difference installing quality aluminium windows and doors will make to your home. That’s why we’re always on hand with the products & experience you need.


Safety & Security

heritage French doors
crittal doors high security
Using police approved multi-point locking systems and the UK’s most secure cylinder, we really have your security covered.

Ultion locks feature:

  • Double snap resistance
  • Unique lock-down mode
  • 11 individual pins (twice as many as standard cylinders)
  • Nearly 300,000 key combinations
  • Anti-drill, pick, and bump


Frequently Asked Questions

What is the maximum width or height per sash?

Side hung windows: The maximum width is 700mm, the maximum height per sash is 1400mm.Top hung windows: The maximum width is 1400mm, the maximum height per sash is 1300mm.Doors: The maximum width per sash 900mm, the maximum height is 2100mm.

Can I choose the configuration of my Heritage doors?

Yes! We offer different variations of our heritage doors based on your preference and requirements.

Can I choose what colour my Heritage window or doors will be?

Yes! Our windows and doors come in a choice of variety of colours including standard and non-standard, metallic and Unique Sensations range of textured finishes. These are available as Single / Dual colour, marine quality polyester powder coated.



Application Domestic
Finish Single / Dual colour, marine quality polyester powder coated
Profile Square
Lock Mechanism Ultion (diamond accredited) Cylinder as std.- multi-point locking
Frame depth


Sightlines 59mm
U Value

1.5 w/m2k using a 1.0w/m2k glass unit

Max sash width 900mm
Max sash height 2100mm
British Standards

KM 81580 / PAS 24:2012 / KM81543 / BS4873

Glazing DG 28mm / TG 32mm
Add ons 20mm, 42mm
Bead Internal Only
Cills 85mm, 150mm, 190mm, 225mm, 300mm
Astragal Bar 20mm / 41mm flat bar

British Manufacturer & Supplier

Over 25 years’ experience supplying Aluminium Windows and Doors..

1000’s of door designs

One of the widest selections of doors, colours, finishes and hardware in the UK.

Free UK Delivery

Impressive lead times & fast delivery service throughout the United Kingdom.

Impressive Security Accreditations

PAS24:2016, BM Trada Q-Mark, Secured By Design (SBD), Document Q & Document M.

Raising The Standard