The transparent roof solution from Copenhagen to the world

October 10, 2023
Olga Kizina

"The transparent roof, esp. the transparent material is a bit like something from science fiction or the Harry Potter movies," says the head of the Nebesys start-up Přemysl Kokeš.“

#innovation roof glass ecology sustainability

At first glance, it is a classic ceramic red roof, as befits and belongs in the historic center of the city. But underneath it hides a lighted attic space, protected by a transparent surface made of glass and aluminum. Residents and visitors can enjoy a panoramic view of the surroundings. It is facilitated by the environmentally friendly Nebesys roof system from the Czech start-up He has just advanced to the final round of the Vodafone Idea of ​​the Year competition, which was attended by 129 innovative companies this year.

"I got the idea for such a roof back in 2011 when the owner of a house from Litomyšl approached me to propose a new roof for his historic building. I told myself that I would improve the attic and that there would be light from the sky under the roof. Thus, the very first Nebesys roof was created for 1.5million CZK. Everyone was satisfied - the owner, preservationists, and myself," architect, founder, and 60 % owner of the start-up Přemysl Kokeštold to Creative Business Network.

Magic light

It was not born immediately after the first project. "For eight years, I waited to see if the heat and cold wouldn't make their mark on the roof. Storms, wind, and snow came and nothing happened to her, everything worked as it should. So three years ago, I roofed our family hotel in Mikulov similarly," added Kokeš. He founded the start-up shortly after, at the beginning of last year. So far, he has completed three jobs and has dozens of orders in the design stage. For this year, he expects sales of over 20 million CZK.

The original solution consists in the fact that triple glazing is placed on the aluminum frame, which can adapt to the various unevenness of old roofs, as a thermal and waterproofing layer. They don't cover the entire roof, that would be unnecessarily expensive. They are usually on half of the roof deck surface, the other part is non-transparent with the above rafter thermo-insulation, i.e. made of sheet metal or PVC. Everything is finally covered with metal roof tiles with hundreds of small holes. Either from specially treated aluminum or from copper. The tiles let in less than a third of sun radiation - it is created by scattered rays from the sky, not direct sunlight, which is perfectly shaded by the perforated roof tiles.

Roof tiles let in less than a third of the sun's radiation. We aim not for direct sunlight, but diffused rays. Then the space under the roof does not overheat.

There is enough pleasant light under the roof without the attic getting overheated. According to one of the company's tests, the temperature rose to 58 degrees C on a hot day under a classic roof with a skylight and stabilized at 27 degrees C under the Přemysl Kokeš nebesys roof. All due to its design - „naturally ventilated roof facade with smart shading“.

The Nebesys system also cools itself – a network of tubes in the battens near the glass plates springs rainwater from the reservoir. On a hot day is rainwater pumped from the tanks onto the roof and evaporates, which lowers the surface temperature. "The roof is similar to the leaves of trees, they also let in only part of the light and cool the surroundings by evaporation," explains the architect.

In addition, the windows do not need to be frequently washed, because the water washes away dirt, including dust, which, due to the nanotechnological treatment of the surface of the upper glass, turns into balls that can be easily removed. So the roof, again similar to tree leaves, also reduces dust in cities.

It is also possible to completely darken the attic with a blind. This prevents the rooms from being seen from a height and a certain angle in the evening after the lights are on.

There is light in the space below it even in winter, when it is covered by a ten-centimeter snow cover. It can even withstand the weight of a 1.5 m thick layer of snow.

Another advantage is the protection of the agricultural landscape from real estate development. If we give a second chance to unused attics there is decreased demand to develop new houses in the suburbs. This is very environmentally friendly while making economic use of the existing technical infrastructure in the city.

Now the company is developing a way to ensure that roofs are energy self-sufficient and that photovoltaics can easily be integrated into them. "It's a great idea, and a Czech one 😊. You can see outside, there is the required lighting under the roof and the thermal insulation is also excellent. Preservationists like that where there is not seen glass under the perforated bags, cooling devices or heat pumps can be hidden," says Pavel Svoboda from the Department of Construction Technology at Technological University in Prague, evaluating the Nebesys system. He even intends to give a lecture about it starting in the fall semester.

From Copenhagen to the world

The start-up has planned expenses of 66 million CZK for the launch. For the most part, he has already gained them from investors. Including the boss, it currently has twelve employees: traders, developers, and people for assembly and production, concentrated in Lanškroun. There are warehouses in Hlinsko and a showroom in Prague Chrášťany.

So far, the customers are from the Czech Republic, sometimes they are attracted by the start-up itself, and other times they get connected through the architects they work with. Not only people come from city centers who need to innovate a classic roof according to the requirements of preservationists. There are more and more people who do not yet have a pitched roof with roof tiles and are just about to buy one.

"The Czech Republic was supposed to be a pilot market for us before we went further into Europe and overseas. Now we have to change our plans a little because we are already being contacted by property owners from abroad," Kokeš points out. A few orders from Germany are already being handled, but more and more are coming from southern countries – Portugal, Spain, or Greece, from where, for example, a hotel in Thessaloniki has contacted us. In these regions, there is also interest in roofs without insulating facades underneath, because it is possible to have a lawn or a garden or BBQ place under the aluminum tiles, through which it rains and air blows.

Abroad, people learned about the Czech company thanks to the fact that this year in Copenhagen it won the Global Finals of Creative Business Cup, the competition for the most creative start-up of the year 2023. "Standing in front of a jury evaluating not only the creativity of the product but above all its business potential was difficult. But Nebesys deservedly won," points out Alena Hájková from the Czechinvest agency. At the same time, the Copenhagen jury also praised the green solution – perforated tiles, historic city roof landscape protection in addition to the aforementioned cooling and dust reduction, can also act as a muffler for urban noise.

So far, the company is benefiting from the fact that no one offers anything similar in the Czech Republic, in Europe, or even in the world.

People from the industry also call the idea a surprise. "We stayed in the Mikulov hotel in the attic, and when we went out on the street the next morning and looked at the roof, my wife asked where the window in the room was. None could be seen from below. I went back to find out and it turns out I work at Nebesys. I also put my savings into it," Jaroslav Nesiba, a builder with experience in a multinational company, told to Creative Business representative. In his new job, he became a sales director.

The company is currently protecting itself with patents. "I want it to be a successful global project that can help change the world. I know it sounds lofty, but it's true," emphasizes Kokeš. According to him, there are more ways to achieve this and he does not rule out selling the company to someone who has the appropriate capital.
But a connection with a strong partner that would help to reach foreign markets, with the right distribution channels, is more likely, closing interview Business Development Manager, Radim Senk.

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