Applications
Flat rooflights, glass roofs and links
Solar Control Roof Glass · Overhead Glazing
HEAT-REDUCING GLASS FOR ROOFLIGHTS
Solar Control
Roof Glass
High-performance solar control glass for flat rooflights, glass roofs and replacement glazing—selected to reduce unwanted solar heat while preserving useful daylight.
Options from 0.29
New & replacement
UK manufacture
10-year IGU seal warranty
Technical support
Specialist project review
More daylight. Less unwanted heat.
CLEAR DETAILS. EASY CHOICES.
Find what you need.
Product information, installation
and documents in one place.
SOLAR CONTROL ROOF GLASS
Designed for your project.
Roof glazing receives direct sun for long periods, so a large or south- and west-facing rooflight can introduce much more solar heat than a smaller vertical window. Solar control roof glass uses a selective coating to reduce the proportion of solar energy entering the room while retaining a bright, relatively neutral appearance.
We specify the coating as part of the complete insulated glass unit. Orientation, glazed area, room use, ventilation, shading, glass colour and the required U-value are reviewed together—because the lowest g-value is not automatically the best result for every home.
SOLAR FACTOROptions from 0.29
APPLICATIONNew & replacement
GLAZINGDouble or triple
THE COMPLETE SYSTEM
Specification at a glance.
Applications
Flat rooflights, glass roofs and links
Projects
New build, renovation and replacement
Solar options
Typical g-values 0.35 to 0.29
Glazing
Double or triple glazed IGUs
Inner pane
Heat-treated laminated safety glass
Toughened panes
Heat-soak tested as standard
Coatings
Guardian or Saint-Gobain options
Assessment
Orientation, area, shading and ventilation
Quoted performance must relate to the final insulating glass make-up. Pane thickness, lamination, cavity, coating position and triple glazing can change both g-value and visible light transmission.
YOUR PROJECT. YOUR OPTIONS.
Choose the right glass and finish.
01
Guardian SunGuard SN 70/35
A balanced option with approximately 70% visible light transmission and a 0.35 g-value in Guardian's published reference double-glazed unit.
02
Guardian SunGuard SNX 60
Stronger solar control with approximately 60% visible light transmission and a 0.29 g-value in Guardian's published reference double-glazed unit.
03
Saint-Gobain COOL-LITE XTREME 61/29 II
A highly selective triple-silver coating with 61% light transmission and a 0.29 g-value in Saint-Gobain's published 6-16-4 reference unit.
04
Performance-equivalent specification
Where brand availability changes, we can specify the required g-value, light transmission, appearance, heat treatment and laminated safety build-up rather than relying on a product name alone.
FROM ENQUIRY TO INSTALLATION
The service to suit your rooflight.
Supply-only is available for suitable fixed flat rooflights. Our specialist systems are supplied with installation by Overhead Glazing; replacement-glass work is assessed individually.
01
Send the rooflight details
Provide sizes, photographs or drawings, postcode, room use and whether the glazing is new or a replacement.
02
Review exposure and comfort
We consider orientation, total glazed area, shading, ventilation and the overheating concern.
03
Select and calculate the glass
The coating, safety glass, cavity and double- or triple-glazed unit are checked as one specification.
04
Approve, manufacture and install
Drawings and performance information are agreed before the bespoke roof glass is produced and fitted.
The roof structure, prepared upstand, waterproofing, lifting and access responsibilities are agreed with your project team before work begins.
YOUR PROJECT PRICE
Quoted to your specification.
Based on the glass, dimensions and agreed service.
LEAD TIME
Agreed for your project.
Programme confirmed after specification and drawing review.
BEFORE MANUFACTURE
Site measure
Ask us to check the opening and installation dimensions.
OUR SPECIALIST TEAM
Installation
Fitting, access and lifting requirements agreed with your project team.
Final cost and programme are confirmed for your specification and agreed scope.
THE DETAIL, FROM EVERY ANGLE
Solar Control Roof Glass gallery.
Select a photograph
to look closer.
Flat and circular rooflights with Guardian SN70/35 solar-control glazing at Fennies Nursery Sutton
Completed nursery room beneath a circular solar-control rooflight in Sutton
Guardian SN70/35 solar-control rooflight at the Sutton nursery
More from our projects
OVERHEAD GLAZING IN MOTION
See our rooflight work.
Our bespoke rooflight film · loads on play
Play film
THE DETAIL MAKES THE DIFFERENCE
Control heat without turning the rooflight dark.
High-selectivity coatings are designed to admit a useful level of visible light while restricting a greater proportion of solar energy. This is particularly valuable over kitchens, living spaces and large glazed extensions.
PERFORMANCE WITH CONTEXT
Performance for your project.
Glass, frame, support and intended use are considered together.
Double or triple glazing?
Compare insulation, weight, solar control and the complete rooflight specification before choosing the number of panes.
Specified for the exact unit
The final g-value and light transmission are calculated for the selected outer pane, cavity, laminated inner pane and double- or triple-glazed build-up.
Replacement glass reviewed properly
We check the existing frame, kerb, sealed-unit thickness, edge support, drainage and access before recommending a solar-control rooflight replacement.
Confirmed for your project
Quoted performance must relate to the final insulating glass make-up. Pane thickness, lamination, cavity, coating position and triple glazing can change both g-value and visible light transmission.
Compare light and solar gain—not just a product name.
A lower g-value means less total solar energy passes through the glazing. The figures below are useful reference points, but the rooflight quotation will state the performance of the actual proposed build-up.
Reference glazing performance
Glass
Light transmission
g-value
Application
Standard soft-coat low-E benchmark
Build-up dependent
≈ 0.47
Smaller or less exposed rooflights where solar gain is not the main concern
Guardian SunGuard SN 70/35
70%
0.35
A bright, balanced solar-control specification
Guardian SunGuard SNX 60
60%
0.29
Large or strongly exposed overhead glazing
Saint-Gobain COOL-LITE XTREME 61/29 II
61%
0.29
High-selectivity roof glazing requiring stronger solar control
Manufacturer figures shown for their published reference double-glazed units: Guardian 6 mm coated glass / 16 mm 90% argon cavity / 4 mm clear glass; Saint-Gobain 6-16-4. The ≈0.47 low-E figure is an illustrative benchmark, not a universal product value. Our overhead safety units normally include a laminated inner pane, so the final calculated values will differ.
Solar control and breakage resistance are separate decisions.
Solar control reduces heat entering the building and can improve summer comfort. Thermal fracture is caused by temperature differences within a pane, often influenced by edge condition, partial shading and glass absorption. Heat-treated glass and a project-specific thermal-safety check address that risk. Spontaneous breakage associated with nickel-sulphide inclusions is a different mechanism again.
BEFORE YOU CHOOSE
Useful answers.
What does the g-value of roof glass mean?+
The g-value, or solar factor, is the proportion of total solar energy transmitted through the glazing. A value of 0.29 admits less solar energy than 0.35 or 0.47, but the final selection must also consider daylight, colour, winter gains, room use and ventilation.
Is 0.29 solar control better than 0.35?+
It provides stronger solar-heat reduction in comparable units, but it is not automatically the best choice. A 0.35 product can retain more visible light and may be a better balance for some rooflights.
Does solar control glass look dark or mirrored?+
Modern high-selectivity coatings can look comparatively neutral, but every product has its own colour and reflection. Samples and the complete glass make-up should be reviewed where appearance is critical.
Can existing rooflight glass be replaced with solar control glass?+
Often, yes. We first need to confirm the existing sealed-unit size and thickness, frame condition, edge support, drainage, access and whether the frame can accept the proposed replacement unit.
Should solar control roof glass be double or triple glazed?+
Both are possible. Double glazing can provide strong solar control with lower weight; triple glazing may improve insulation but changes weight, light transmission and the calculated solar factor.
Will solar control glass stop thermal breakage?+
No single coating can guarantee that glass will not break. Solar control addresses heat entering the room. Thermal-stress risk is assessed separately through glass type, heat treatment, edge quality, shading and the complete glazing detail.
Is a laminated inner pane still required?+
Solar control does not replace overhead safety design. We specify a laminated inner pane so broken fragments are retained, with the exact build-up selected for the rooflight size and loading.
What information do you need for a quotation?+
Send the approximate outside kerb size, postcode, photos or drawings, room use, orientation if known, and whether this is a new rooflight or replacement glass.
What warranty applies to this product?+
Qualifying insulating glass units carry a 10-year seal warranty, subject to the written terms supplied with the order. This is not a blanket guarantee against breakage or a 10-year frame or installation warranty. Installation labour carried out by us is covered for five years, subject to the written terms.
CUSTOMER FEEDBACK
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LET’S TALK ABOUT YOUR PROJECT
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PROJECTS & PRACTICAL ADVICE
From the drawing to the roof.
PRODUCT IN CONTEXT
Solar-control rooflights at Fennies Nursery Sutton.
Three rectangular rooflights and two circular units were specified with Guardian SN70/35 solar-control glazing for this nursery renovation. The case study explains the daylight brief and crane installation.