Reinventing the rooftop

As urban living intensifies in density and numbers, the city landscape expands both outwards and upwards. Architects and urban designers craft new and experimental structure while also investigating existing buildings for potential reinvention or expansion. In particular, the roof of a building, once a perfunctory structural element, has to be reinvented and becomes a city space in and of itself, beloved for the capacity to eke out further room for living or to craft inspiring refuges away from the bustle of the metropolis. (TASCHEN)

Inspiring examples

For those who focus on creating new living spaces on roof, the book ROOFTOPS, Islands in the Sky published by TASCHEN is an absolute must. The author (Philip Jodido) gives you a breathtaking overview and describes about 50 examples from all corners of the world, including bars, restaurants, contemporary installations, gardens and parks. Masterfully photographed and illustrated by the Korean Boyoon Kim. 

Whether it’s the panoramic views, the exposure to the elements, or a slight giddiness that comes with height, we see just how the roof has nurtured not only architectural invention but has also brought a whole new facet and thrill to city living.

Copyright: Javier Callejas / TASCHEN
As with all books in TASCHEN’s architecture series, it also celebrates both the established and the rising talents of the industry. Featured artists in this movement towards the skies include Pritzker Prize winners Norman Foster and Shigeru Ban, Jeffrey Inaba, Julien De Smedt (JDS), and landscape designers such as Ken Smith and Valdimir Djurovic.



Futureproof solutions

Actively used rooftops hold higher building standards than other roofs. Creating environments with new life on roofs requires choices of materials that guarantee a long-lasting, sustainable and heavy-duty construction.

Imagine having a park, a swimming pool or even a restaurant on your rooftop. For these types of living spaces, you want to minimize the risks, e.g. leakage and impact on the building. The risk of leaks is higher with Active Roofs than on other types and searching for the origin can lead to costly repairs and renovations.

With FOAMGLAS® thermal insulation you can realize your dreams and rest assured that your roof has the highest safety standards. It offers all the guarantees you need and comes with extra beneficial qualities for creating heavy installations. FOAMGLAS® has solutions that will provide you the optimal application for every type of load.

Most applications can be done with a FOAMGLAS® standard solution: Compact Roof. 


> Green roofs with intensive vegetation
> Roof constructions involving water like ponds and swimming pools
> Infrastructure, e.g. parking or ventilation units
> Rooftop constructions such as restaurants, sport facilities, greenhouses etc.
> Photovoltaic systems


All these construction possibilities are made possible by the exceptional characteristics of FOAMGLAS®.  The thermal insulation material has all the qualities and properties required for safe and sustainable constructions on rooftops.

>> Take a look at them




Using the same standard insulation build-up for your entire roof, your possibilities are nearly limitless. You can create areas with vegetation, playing fields or water sections, as well as parking lots and areas with solar panels.

And the best part is that you can even do it years after installing FOAMGLAS. You always retain that flexibility.


Our compact roof enables you to alter the rooftop application without changing the original construction (provided the building’s structure can take the load). So you retain the flexibility of having different options while reducing cost and waste.


Some of our oldest roofs have been in place for over 4 decades and still provide same high-level performance as they did on the day they were installed. Even over exceptionally long periods, FOAMGLAS® retains its strength, thermal performance and all its other exceptional properties. Due to its time-tested performance and easily replaceable membrane (peel off and replace), your roof lasts a lifetime, and that means lower costs and less waste.

The FIW in Munich put our product to the test. Their results are proof of its consistent performance over time.

>> Read more


With rooftops serving as new areas for living and relaxation, it is of the utmost importance to provide safety for people and the building. Fire safety is one important part. Awareness of that has significantly increased in recent years.

Insulation material like our cellular glass insulation provides an incombustible solution for your active roof. And that does not only improve your building’s fire safety; it also adds valuable time for people to evacuate and for firefighters to perform their task.

>> Read more






Loads such as greenhouses or even large plant/tree containers on a rooftop can lead to deformation and movement of building materials. Movement can cause a membrane to age faster. Many solutions also require an extra layer on top to distribute the load. This involves extra costs that are avoidable.
+++ FOAMGLAS® special cell geometry ensures a high compressive strength which can bear long-term loads without the need for an extra load distribution layer. With FOAMGLAS® you can rest assured that there will be no deformation.

Green roofs, rooftop parks and similar setups often face problems with leakages due to root penetration. With many building materials humidity and moisture result in severe consequences for the building. Any leakages into the building have impact on its overall thermal performance. And in addition to that, with most materials it is nearly impossible to detect the origin of the water penetration without completely ripping everything off and re-installing the roof build-up.
+++ FOAMGLAS® is water proof and vapor tight. It comprises hermetically sealed glass cells and will not absorb any moisture. In the event of leaks that might occur due to drilling, the origin is easily detected as the damage is only local and therefore easily remedied.

Imagine having a forest-like area on your roof with tall trees and forest plants – a little bit of nature in an urban surrounding. While extensive vegetation (small plants, grass etc.) is possible with many materials, intensive vegetation imposes high requirements to the whole roof build-up. Intensive green roofs do not only require a high load-bearing solution; they also come with the risk of roots damaging underlying building materials. Roots normally search for water everywhere – even in between materials. 
Additionally, if there is leakage, materials may start rotting and/or vermin find space to nest in them. And that endangers your building’s safety.
+++ FOAMGLAS® is one of the few materials on which you will be able to have extensive and intensive vegetation without any risks. Its compressive strength is able to bear the heavy loads associated with intensive green roofs. There is no need for a load distributing layer, e.g. concrete. Furthermore, plant or tree roots cannot pass through its sealed glass cells. FOAMGLAS® cellular glass cannot rot and is resistant against vermin. It acts as a protective shield for your building. 

If you are planning to use your roof for vegetation or urban farming, your awareness towards sustainability, recycling and environmental management is probably high. Not all building materials are suitable for your project. Some might not last long. Others are not easy to recycle after replacement. 
+++ Using the right building material can be crucial for your green roof. FOAMGLAS®, for instance, is capable of maintaining the same thermal performance for many decades, ensuring consistent energy efficiency. In addition to that, it is actually made of recycled glass by 66% and is recyclable itself.



Solar systems impose heavy loads on a roof as they are exposed to wind and snow. That is why an extra concrete socle is applied below many of these installations. However, the concrete below the solar panels functions as a cold bridge meaning that it is easy for heat to leak out of the building and cold to penetrate it.
+++ FOAMGLAS® cell structure offers a high compressive strength, which can bear long-term loads without any extra socles. And that means you have a one-layer solution with a continuous insulation application. So your building is fully protected against unwanted cold bridges.

For maintenance purposes, it is essential to have access to these highly technical systems. In many cases it is important to decide in advance where to place the solar panels and specific locations for setting up walkways – and that reduces flexibility. 
+++ With FOAMGLAS® you remain flexible. The cellular glass insulation is rigid, and there is no risk of deformation under solar panels or walkways. Even years after installing FOAMGLAS®, you can decide to install a solar system or change your roof into nearly anything you like (a sports field, park, greenhouse, etc.). 

The wind load on solar panels can be intense. Therefore, a solid and high load-bearing material is required under the solar system to keep it in position and avoid any deformation. A concrete slab is often used to hold the solar panels in place. Not all materials can endure the additional high load on top without deformation and movement. After a while replacement or repair will be inevitable. Besides that, the newly created cold bridge, due to the concrete, will reduce the building’s thermal performance.
+++ It is not necessary to install an additional concrete slab on top of FOAMGLAS®. Our cellular glass insulation can bear the heavy load of the solar system as well as the concomitant wind load. There will be no deformation or movement.

Solar system fixings can result in leaks as they penetrate below installation. For some building materials water penetration can result in severe consequences regarding their thermal performance. And the water will leak into the building. 
+++ FOAMGLAS® is water proof and vapor tight. It consists of hermetically sealed glass cells and will not absorb any moisture. The cellular glass insulation protects against the risks of leakages as water cannot find its way through the layer of completely water proof FOAMGLAS® insulation. 

Solar systems involve a lot of electrical power and the presence of electricity can imply a high fire risk. 
+++ FOAMGLAS® is an incombustible insulation material which neither promotes fire nor produces fumes. It will even help contain the fire locally. So it will improve the fire safety of your building. 


Roof terraces are lounge areas for relaxation. People enjoy using them throughout the year. Local heavy loads on the rooftop can result in deformation and movement if the insulation layer underneath is not strong enough. 
+++ FOAMGLAS® cell structure provides high compressive strength and can bear loads over extensive periods. You can rest assured that your outdoor kitchen, plant containers or chill-out area will not cause any deformation of the FOAMGLAS® application.

Summer time is a welcoming period to enjoy the roof terrace. It is also the time where the risk of fire increases as many people love having BBQ or outdoor fireplaces
+++ FOAMGLAS®, as an incombustible insulation material, will not spread fire and does not produce fumes. It actually helps to contain the fire locally. Once installed, it improves your building’s fire safety. 

Many building materials are not resistant to chemical impacts like polluted rain, weed-killers and suchlike. Over time, those factors can have an impact on an Active Roof. 
+++ FOAMGLAS® comprises pure glass and is therefore resistant to organic solvents and acids. The installed application and its performance will retain as well as your roof.

Once in a while, it is nice to have a change. As rooftops increasingly become extensions to the living area of buildings, you might want to change the purpose of your Active Roof into something new sometime in the future. Not all applications will be able to offer you flexibility and possibilities to change from, for example, a roof terrace over a green roof into a sports field.
+++ Using FOAMGLAS® for your roof application will maintain your flexibility. Would you like to have a playing ground now but change it to a green roof years later? Perhaps you would prefer to convert it into a park area or have a mix of all? Even years later, you can change your roof terrace if it is based on FOAMGLAS®.


Parking decks require a heavy load bearing solution. Otherwise, daily use can result in deformation and movement of materials, and thereby damage to the building itself. Leaks are one of the problems that can occur, and the origin is normally hard to detect, so that you can only repair by completely replacing the existing application. 
+++ FOAMGLAS® cell structure provides a high compressive strength which can bear long-term loads – no deformation, no shrinkage. Even in the rare event of a leakage, the damage is easily detected as water cannot get through the cellular glass and the leak will only be local. 

Risks of fire on parking decks might not be that obvious at first sight. However, cars can catch fire and and therefore represent a fire risk. 
+++ FOAMGLAS® has the European fire classification A1, meaning that is it an incombustible material. In the event of fire there is no propagation of flames. FOAMGLAS® serves like a protective shield.

A parking deck means heavy load on a roof. Depending on used building materials the load might result in deformation of the insulation layers and thereby, lead to potential water leaks by putting extra strain on the membrane. Such leakages can result in significant reduction of thermal performance, among other things. With most applications the water travels through the materials making it nearly impossible to detect its origin. It often results in very costly repairs and replacements.
+++ Besides its compressive strength (thus no deformation), FOAMGLAS® is also water proof and vapour tight. It consists of hermetically sealed glass cells and will not absorb any moisture. It will protect the integrity of your parking deck against the risks of water and moisture penetration. In cases of leakage that might occur during drilling, the damage remains local. And that means only local replacement is required.

Leakage membrane = infiltration in and under the insulation  Water and vapour tightness

  • Insulation becomes wet
  • Difficult to identify the location of leak
  • Vapour barrier to be included: risk of errors

  • FOAMGLAS® = closed cellular glass = water and vapour tight
  • Compact roof = fully bonded to the support and closed joints
  • Together = massive water / vapour barrier in entire thickness
  • No infiltrations: insulation remains dry and effective – no leakages
  • No condensation: insulation remains dry and effective – no leakages – no corrosion – no need for vapour barrier
  • No degradation of thermal performance: no loss of R-value
Parking decks have to endure chemicals like oil and petrol. Those chemicals are aggressive and if they permeate through joints, they easily damage the building envelope. 
+++ Consisting of pure glass, FOAMGLAS® is resistant to organic solvents and acids. The parking deck and its performance will endure as well as your building envelope.


Sport fields or playing grounds invite to activities. Rooftop constructions like restaurants, apartments, greenhouses and similar structures are inviting for comfortable meetings and cozy get-togethers. All applications incur local heavy loads on rooftops. Using the wrong materials can result in deformation and movement, endangering the entire building. 
+++ FOAMGLAS has high compressive strength and due to its cell geometry can bear heavy loads over extensive periods. No matter what you decide to install on top of FOAMGLAS®, the cellular glass insulation material will not deform or move. 

Areas frequently used by people should always offer a higher level of fire safety. Many building materials are fire tested and provide a certain amount of safety. However, in the event of a fire, additional aspects such as smoke formation, toxic gases, propagation of flames and much more need to be taken into account. A wise choice of material is essential. 
+++ FOAMGLAS® has the European fire classification A1, meaning that is it an incombustible material. In the event of fire there is no propagation of flames, no release of toxic fumes and no production of smoke. FOAMGLAS® will help containing the fire locally and serve as a protective shield.

It is nice to have a change occasionally. As active roofs become living spaces for people, it can be nice to have options for converting your current roof into something else. Not all roof installations will be able to offer you that kind of flexibility when the time comes.
+++ Using FOAMGLAS® for your roof application allows you to remain flexible. Would you like to have a sports field, but perhaps change it for a greenhouse years later? Or perhaps you want to change it into a restaurant or have a mix of all those things? With FOAMGLAS®, you can convert your roof to suit your needs, and even do it years later.



Rooftops with water tanks on them have to bear heavy loads. Not all applications are capable of enduring such loads over time. Deformation and shrinkage can result in unwanted movement.
+++ Due to the FOAMGLAS® cell structure gives the cellular glass insulation a high compressive strength. It can bear long-term loads without deformation or movement.

Water tanks are installed on rooftops, so that firefighters have easy access to water in an event of fire. 
+++ FOAMGLAS® is an incombustible insulation material with European fire class A1. It will improve the fire safety of the building on which it is installed. It ensures that there will be no propagation of flames in the event of a fire.



We have numerous references for Active Roofs. Here we show you a few projects. Consider for a moment the added value you can give to a building or to the appeal of a public space and remember: the future is built today.


Nijmegen, The Netherlands


Mecanoo architecten, Delft, The Netherlands

FOAMGLAS® compact roof for a grass roof, including water buffering

More than 10,000 m² of roof surface, but no connection to the local sewer system. The 17-floor building caused additional critical rain load on the adjacent roof area. 

Given the intensive use of this roof, FOAMGLAS® compact roof was the safest and most durable solution. FOAMGLAS® provided a completely waterproof application that was glued to the roofing layers. It was possible to integrate a special drainage, i.e. a buffer layer into the grass roof to handle up to 40% of the rain volume. The remaining 60% is collected by gravel containers which release the water slowly to the ground. FOAMGLAS® has high compressive strength and it is capable of bearing these heavy loads over very long periods.


Campus Aalst, Belgium


VK group Healthcare Roeselare, Belgium

FOAMGLAS® applications for several purposes like parking, greenery, terraces etc. 

The more than 100-year-old hospital was designed according to sustainable, conscious building methods. The building extension was no exception since green roofs, underfloor heating, a clever sun protection and much more were planned for the building.

The building owner’s and architect’s knowledge of FOAMGLAS® insulation and its exceptional properties inspired them to choose using FOAMGLAS® exclusively for all different roof applications, such as parking, vegetation and much more. The insulation material can bear heavy loads , while also providing fire safety, water proofing and vapour-tight solutions.


Berlin, Germany


Building owner
Siemens AG, Siemens Real Estate – Region Ost, Berlin

FOAMGLAS® compact roof for intensive/extensive vegetation and lounge area

For the main building Siemens Real Estate (SRE) planned representative and accessible roof terraces including intensive vegetation. It was important to provide a pleasant atmosphere. 

SRE chose FOAMGLAS® due to its exceptional properties. The cellular glass insulation is water proof, an important requirement for greenery on any actively used roof. Completely sealed glass cells prevent the water penetration. FOAMGLAS® is also resistant against root penetration, enabling intensive vegetation on the roof surface without any risks. Finally, intensively planted areas and plant containers implied a requirement for high compressive strength, as they imposed additional heavy loads on the surface. FOAMGLAS® compact roof provided all the required conditions.


Wattens, Austria


André Heller (künstlerische Leitung)/ Mag. Carmen Wiederin und Propeller Z, Wien/ Ing. Georg Malojer, Projektmanagement GmbH & Co, Innsbruck

FOAMGLAS® roof applications for extensive greenery 

The roof system of the “Swarovski Crystal World” extension had to meet the highest standards. Any repair or renovation of green roofs, especially of this size, involve considerable costs and may seriously disrupt operations. Therefore, long-term insulating performance with high compressive strength were decisive criteria.

The original construction of the “Swarovski Crystal World”, already used FOAMGLAS® as insulation material. It had proven its consistent high thermal performance as well as it is absolutely weatherproof. Additionally, the roof structure is under a meter-deep layer of bulk. FOAMGLAS® can bear the high-level of pressure from the soil over the long-term, due to its high compressive strength that eliminates deformation.


Copenhagen, Denmark


JJW Arkitekter

FOAMGLAS® compact roof with wooden terrace and greenery

Schools always have high safety standards for their pupils and students. For Sydhavnsskolen it was a requirement to build a safe environment for the children to invite them to be physically active. Therefore, the insulation material needed to be incombustible to ensure high fire safety standards. Additionally, as there was also vegetation / greenery planned, the roof not only had to bear heavy loads but also required a completely waterproof application. 

Sydhavnsskolen decided to go with the FOAMGLAS® compact roof: the all-in-one solution for their requirements. FOAMGLAS® products are able to bear high-loads over the long-term. Additionally, FOAMGLAS® itself is water-resistant and incombustible. The cellular glass insulation has European fire classification A1. Thereby, improving the building’s fire safety when installed.


Maastricht, The Netherlands


AMA Group Architecten, Maastricht

FOAMGLAS® compact roof for pedestrians

The combination of housing, shops and restaurants with an already existing building challenged AMA Group Architects. The demands on the insulation sub-construction – on which a pavement with clinker finish would be applied – were high. In general, the area is exclusively for pedestrians, but several places need to withstand greater load when e.g. when supplying the shops and catering businesses.

FOAMGLAS® compact roof convinced AMA Group Architects in regard to its exceptional properties. It met all the requirements: a waterproof system with high compressive strength that will last as long as the Entre Deux itself.