Our Structural Glazing Options

Structural Glass Roofs | Glass Lean To Roof | Frameless Glass Rooflights | Sliding Rooflights

If you are in the process of choosing some improvements to your home or other buildings, rooflights by Natralight might be the perfect option. With more than 30 years of experience when it comes to structural glazing, we can create some truly stunning rooflights with practical features.

Lean to Glazing

What Rooflight Types Do You Supply?

Our range includes off the shelf options, as well as completely bespoke units. The main rooflight types we supply are:

Sliding rooflights – Our sliding rooflights feature a side opening mechanism for maximum ventilation as well as letting in natural light.

Frameless glass rooflights – Frameless glass rooflights use the latest in rooflight technology: glass to glass joints.

Glass lean to roof installations – Ideal for connecting different areas of your property in a glass link style, or for creating extra interior space.

Structural glass roof installations - An impressive option for buildings pf all kinds, creating a dramatic look internally and externally.

Do I Need Planning Permission for Rooflights?

Planning permission is not normally needed for rooflights or re-roofing your home as Permitted Development rules allow for roof alterations.

There are some limits and conditions, including no alteration should project more than 150mm from the existing roof plane or be higher than the highest part of your roof. For side-facing windows they require obscured glazing and any opening has to be 1.7m above the floor.

Some local authorities have different rules regarding Planning Permission on what is possible, with regards to rooflight installations. This is the reason why you should always consult your architect or an expert such as Natralight about this matter.

Is My Roof Suitable for Rooflights?

Our rooflights can be installed in all kinds of roofs, but some are better suited to certain roof types than others. The best way to know whether sliding rooflights, frameless glass rooflights, or structural glass roof and structural glass roof installations are going to be best for your property is to get in touch with us. Our experts are always more than happy to discuss your options and help come up with the perfect design.

Having an in house design team lets us match your rooflights to your building perfectly. Some of the roof types we regularly work with include:

Gabled or pitched roofs

Flat roofs and roof terraces


M-shaped roofs


Of course, there are more unusual roof types out there which are just perfect for rooflight installations. If your roof is one of these more unusual varieties, get in touch to discuss your requirements with us.

Are Rooflights Difficult to Keep Clean?

Glazing technology is rapidly becoming more high tech, and this has led to some fantastic developments in glass care. For example, special glass coatings can be added to your rooflights which keep dirt and grime at bay. This means you can enjoy a clear view for longer! As and when needed, the rooflights can be cleaned like any regular glazing. 

How do the Rooflights Operate?

While our fixed rooflights and walk on glass do not move when in situ, we offer a complete range of opening rooflights. An example would be our sliding rooflights; these feature glass panels which slide over one another to form an opening. We also design and manufacture hinged opening rooflights which open more like a traditional window.

 A choice of operating mechanisms adds the finishing touch to your new installation. Manual operation is a popular option whereby the rooflights need to be opened by hand. This is convenient for rooflights within easy reach, but for more difficult to access installations we offer the option of remote controlled opening. For the ultimate in rooflight convenience, however, you can opt for our top of the range automatically opening and closing rooflights complete with rain sensors. 

Do Your Rooflights Come with a Warranty? 

All our rooflights come with a minimum five year warranty for your peace of mind. We are also members of several organisations such as UKAS.

What are my U Values?

U values are a calculation that are created due to the loss of heat through any building element per square meter of surface for one-degree difference between the internal and external temperatures.  This calculation helps to determine the thermal performance of glazed structures.  

The U values are measured in watts per square meter per kelvin (W//(M²K)). Each degree difference in temperatures between the inside and outside of the window is transmitted every square meter depending on what watts per square meter it's measured at. 

What does UW Values represent?

UW values are a calculation of heat loss through glass, edges and the frame.

Do I need a heating element near the rooflight?

Natralight would recommend a heating element is placed underneath the skylight, in order to minimise condensation on the pane.

What is the minimum distance needed between two rooflights?

If you have chosen to have individual roof lights, we would recommend putting two tiles in between, with an approximate distance of between 40-60cm.

Is a glass rooflight better than a plastic rooflight? 

Rooflights from Natralight are superior to plastic in every respect, offering better energy efficiency and durability. Glass skylights also reduce external noises, won't discolour, allow drafts or leak.

Why do rooflights have a black band around the perimeter?

The 115mm silkscreen band around the perimeter rooflights is for the UV protection of the sealing and upstand.

Do I need planning permission for my skylight?

In England and Wales planning isn't usually required to have rooflights installed, subject to the current limits and conditions by the government's Planning Portal under Schedule 2, Article 3, part 1, class C permitted development.

Is scaffolding needed to install or replace a rooflight?

This depends on the location of your rooflight. If you are unsure we recommend having one of our engineers attend your property to complete a site inspection. 

Can Water Pool on the Glass of Rooflights?

Glass is considered a rigid material and will still deflect under load, the same as all rigid materials.

The rigidity of glass deflection is dependent on the glass pane size, so the bigger the unit the less rigid it is and more deflection will occur which starts at the centre of the pane. When installed in the horizontal plane the glass will start to dip or dish in the centre with the deflection due to the self-weight of the material (sometimes referred to as the dead load) plus live loads like wind pressure or snow loads. If a liquid like water were placed upon the glass, it will fill the dish creating a pooling or ponding effect. 

Flat rooflights are installed onto a kerb with at least a 5° fall, which helps shed any water that can pool on the deflecting glass. If a flat glass unit was installed at 0° pitch it would not be a detriment to the weathering or integrity of the IGU unit except water pooling on the top glass surface.

For water pooling to be eliminated entirely, the thickness of the outer skin of glass must be increased so that the deflection is reduced to almost zero. To make rooflights safer the glass is heat toughened to make it stronger. Water can also cling to a vertical pane of glass via capillary action, so water can never be completely removed by simply pitching the kerb slightly.

Can I have an unusual colour of frame for my rooflight?

Natralight provides flat glass rooflights with other RAL colour frames, however, the lead-time and costs will be higher than the standard stock options. 

What is cold bridging?

Cold bridging is when condensation forms on the inside of the rooflight framework, which commonly occurs when the skylight has been installed in a high humidity room such as a bathroom or kitchen. Natralight offers rooflights with trickle vents within the kerb/upstand or manual or electric opening to help eliminate the issue.

My flat roof has a slight pitch, can I have a flat glass rooflight?

Yes, flat roofs are suitable for mounting at pitches at 2-15”. The flat glass rooflights are ‘flat’ and so are the kerbs, with the pitch of 2 inches, should be on your roof already to enable rainwater to run off. This is not always the case, however, and if you have a ballasted roof you will need to make sure the roof openings are pitched accordingly. 

How Much Roof Space Is Needed for a Rooflight?

You will need the window width plus 20mm-40mm and the window length plus 20mm-40mm and ensure that the top trimmer is fitted in a horizontal position and the bottom trimmer is fitted in a vertical position. 

What is Heat Soak Testing?

Heat soak testing is a process that can be carried out on the glass and involves placing glass that has already been toughened into another oven and heated to temperatures up to 290ºC, then holding it at the temperature for a pre-set period (roughly 2 hours). This is believed to reduce the risk of spontaneous failure by up to 99%.

Glass Balustrades

Do glass balustrades meet Building Regulations?

Most systems comply with current Building Regulations, but if you are unsure of specific requirements we would recommend checking with a building inspector.

What is a frameless glass balustrade?

A balustrade manufactured from a quality toughened safety glass with metal fixtures and fittings that are attached to a metal handrail. 

Are frameless balustrades suitable for homes?

Yes, Natralight has rich experience working on many residential properties, flat roofs and as replacements for ageing wooden stair bannisters and rails which create a visual barrier and a decorative outside patio. Balustrades can also be used where internal levels change plus stairwells. 

Frameless glass balustrades are ideal for homes plus bars, shops, restaurants and offices. 

What is the best height for glass balustrades?

Building regulations state balustrades should be 900mm high on stairs and 1100mm everywhere else.

What is a structural glass balustrade?

A structural glass balustrade is based on two engineering principles; a strong base that clamps thick and strong glass panels and resists the bending moments and loads imposed on it. 

BS6180 was revised in 2011, and not it is possible to choose if you do or do not want a handrail. The handrail or top section which is placed on the glass is meant to tie glasses together at the top, making the whole structure sturdier and more solid. 

It must also be able to withstand the required load if one of the glass panels breaks across the gap created. If you choose not to have a handrail, laminated glass needs to be used plus glass that can have one side break with the other side still capable of withstanding the loads.

What's the difference between laminated and toughened glass?

Laminated glass is the windscreen of a car, whereas toughened glass is on the side and rear windows. Toughened glass is up to five times stronger than regular glass, which means it is more resistant to force before breaking. Toughened glass, when broken, becomes thousands of small pieces of glass that is considerably less dangerous than glass shards. 

Laminated glass is ordinary glass but is two panes that are sandwiched over a plastic inner layer and if the glass breaks the plastic layer holds it together with no glass shards and the whole piece remains together even though it's broken. 

Roof Lanterns 

Do roof lanterns apply to any home design?

Every property is different, which is why Natralight offers bespoke rooflight designs with different sizes, light transmissions, ventilation options and shapes.

What size roof lantern is best for my home?

Every property is different, as this will depend on how the area below is used, personal preference plus the amount of natural light you want to generate. 

Remember that the upstand/kerb that your roof lantern sits on needs to leave sufficient clearance all round for general maintenance of the roof itself. Typically 300mm minimum clearance is needed although you might get away with slightly less.

What is a Thermal Break?

A thermal break is a material with a low thermal conductivity that is placed between two different conductive materials. Its purpose is to reduce or prevent the flow of thermal energy. 

What is the Difference Between a Roof Lantern and a Rooflight?

The main difference between a rooflight and a roof lantern is that the roof lantern is a pitched structure that sits on a flat roof, whereas a flat rooflight is fitted into the construction of your roof. 

Can I Hang a Light from the Middle of a Roof Lantern?

When you have a roof lantern you can add a pendant light fitting. Please discuss this with our team when you are considering having a roof lantern installed.

Is My Roof Strong Enough for a Rooflight or Roof Lantern?

The strength of a regular house roof will not pose issues for rooflight installation but single-storey extensions with a flat roof are not designed for the weight of a roof lantern. Natralight would advise consulting a structural engineer to prepare a report which is required by the Building Control department of your Local Planning Authority. 

Structural Glass

What is structural glass?

Structural glass refers to any glazing that is taking on the bearing of the structural load. This type of glazing can be used for different projects such as glass floors, balustrades and facades.
Glass facades are commonly used for extensions as the glass is thick and strong enough to go without a framing system. Instead, it is kept in place by hidden channels and steel angles, which are made especially for your home and give you uninterrupted views of your surroundings. 

Is structural glass energy efficient?

Structural glass does not require a frame, meaning it can be as thick as you like and perfect for insulation. It is also thermally efficient, meaning you do not need to measure its U-values, unlike other types of glazing. 

What are the Advantages of Structural Glass?

The glass used is thicker and stronger which means you do not need framing systems to support the installation. As the glass is fixed to the building structure with bespoke fixing details to suit the building makeup. The fixing details are often hidden channels and steel angles that hold and fix the glass into the building. These elements can be hidden by the building finishes which creates a clear glass installation. 

You are not governed by any maximum sizes of framing systems or maximum glass weights for facade systems which means you can create a huge installation of glass with architectural glazing. 

If you are looking at creating a glass box structure or a frameless glass facade the biggest piece of glass you can use is governed by access to the site plus the budget of the project. This allows architects and designers to further scope when creating striking and innovative building designs.

Fire-Rated Rooflights

Is the fire-resistant glass suitable for external applications?

All non-insulating glazing is suitable for both internal and external locations.

What size of frame is required for fire-rated glazing?
The size of the frame will differ considerably from one product to another; with no standard formula. Consideration must be given to whether insulating or non-insulating glazing is required. 

Are skylights suitable for use in conservation areas?

Yes, it is common for us to design and manufacture flat roof skylights for this type of application. This type of roof is low lying and installed on a 5° pitch which allows water to run off. 

What Should I Do if there is condensation on the inside of my pane?

Firstly, ensure your room is adequately ventilated and be aware that condensation on the inside of the pane comes from not having a heat source underneath the roof window. The interior lining should also be horizontal over the rooflight and vertical under the rooflight, ensuring an optimum flow of air and maximum light.

What is Fire-Rated Glass?

Fire-rated glass is a specialist glass that is proven to protect against fire with a degree of protection offered depending on the type of glass. Generally, the glass acts as a barrier to stop the spread of flames and smoke in the event of a fire. The degree of protection offered is given in time periods that range from 30 minutes upwards. 

Can Safety Glass Withstand Fire?

Safety glass does not withstand the thermal heat produced during a fire and will not provide a sufficient fire-resistant barrier required under the regulations. 

What is the Difference between Fire-Rated and Safety Glass?

Fire-rated glass stop or limits the flames, smoke and heat from a fire for a specific period of time that depends on the type of glass used plus how it is installed. Safety glass is typically laminated or toughened glass that is harder to break and does not shatter in the same way as ordinary glass. This is either due to the specific processing the glass has undertaken during manufacturing or the bonded interlayer within the glass. Please note, safety glass does not have any fire resistance.

Can Fire-Resistant Glass be Installed into Frameless Systems?

Specialist glass and glazing systems that have the appropriate fire test evidence can be installed into frameless systems. Get in touch with Natralight for more information on this. 

Walk-On Glass

How Safe is Walk-On Glass?

Walk-on glass floors are designed to be as secure as concrete beneath your feet. Layers of toughened glass are bonded together, forming a safe and strong surface that it suitable for pedestrians to walk upon.
Different walk-on glass thicknesses are available for different projects, and we can advise on the number of layers you should choose for security purposes. The glass also incorporates a tough anti-slip surface on the top that is certified as high as R-11, which prevents the glass from causing falls. 

Is Walk-On Glass Easy to Clean?

Walk-on glass panels are surprisingly easy to keep clean, and if required they can withstand power hosing. This is unlikely to be necessary as the material can be treated using a self-cleaning coating that deters dirt, stains and debris. 

Is Walk-On Glass for Internal or External Use?

Walk-on glass enhances both internal and external projects. For interior design, glass provides the perfect finish whether it is installed as glass stair treads or a striking feature floor in a commercial setting such as a restaurant or bar. 

For areas where natural light is limited, toughened walk-on glass is the ideal choice. This could be walkways, roofs or terraces where you want to maximise the amount of light. 

Can Glass Floors be Used in Outside Decking?

Exterior decking is a great practical use of glass floors. When looking at decking with glazing you will need to ensure it is completely waterproof. 

How is Glass Floors Installed?

Once plans for a glass floor have been drawn up, the framing perimeter is affixed to the wall and supported underneath by beams. Framing spacers are then set for the first row of glass panels plus cushioning strips. The edges of the glass are taped to prevent chipping and are set into place. Once all of the panels have been laid, the edges are sealed with silicon and the tape is removed. The floor can be used once the silicon is dry. 

Glass Roofs

Are Glass Roofs Quieter than Polycarbonate Ones?

Polycarbonate roofs offer very little in terms of noise reduction with heavy rains and strong winds easily heard inside conservatories. This makes it difficult for some people to relax. 

Alternatively, glass roofs offer far superior noise reduction and will ensure you can still enjoy time in your conservatory. 

Can Glass Roofs Be Cleaned?

Glass roofs require a minimum slope of 1% which allows rainwater to help wash away any debris, dust and leaves that settle there. Typically a slope of 5% or more guarantees a decent enough incline which keeps it relatively clean in wet weather or when it needs washing. 

We would recommend having a good space against which to prop a ladder for maintenance, whether you do it yourself or have a specialist to clean your glass roof. 

How Do I Maximise Light with Glass Roofs?

Glass roofs look spectacular when supported by glass beams that are toughened and laminated which ensures maximum light comes flooding into your home.

Could I have a Fully Glazed Roof?

If you are looking to refurbish a loft space, you could consider add glazing to your entire roof and let plenty of natural light in. You may need to check Planning Permission first because of privacy and overlooking issues. If you are unsure about any area of planning permission, give your local duty planning office a call for some advice. 

What Treatments Can Be Applied to Glass Roofs?

A number of treatments can be applied to glazing to enhance your home's properties. Here are three to consider -

Solar Control - Having a glass roof or ceiling can run the risk of having your space overheating in the summer but with solar control you will be able to keep the light pouring in, but not the heat. 

Privacy - Using this sort of treatments means you can still see the sky without your neighbours seeing inside. This can be the ideal choice for glass roofs being installed in densely packed areas such as London.

Heated - If you live somewhere prone to snow you could also consider heated glass, which uses electricity to keep your property warm, melts snow and eliminates condensation. Heated glass can also be used as another heat source that is ideal for high ceiling properties.

How Can I Get a Quote on Your Rooflights?

You can get a quote on our rooflights, discuss your requirements, or get some more general information by giving us a call, or filling in the form on our ‘Contact Us’ page. We are always on hand to offer you any help, advice and information you may need when it comes to our rooflights and structural glazing.