Skip to content
Christian Reingruber © Daniel Hinterramskogler

Sustainable roof systems: “From protection to multi-function”

Photovoltaics, roof renovation and innovative strategies for the future: Christian Reingruber, Chief Strategy Officer (CSO) Roof Solutions and Applications, is driving the development of sustainable roofs at wienerberger.

10.11.2023 9 min

You have been Chief Strategy Officer for Roof Solutions and Applications at wienerberger since July 2023. What does your job involve?

Christian Reingruber: My role is to further develop wienerberger’s strategy in the area of roof solutions and applications. Together with my team I focus on how we can meet customer needs even more effectively and thus increase customer satisfaction. In addition, we identify opportunities for growth – for example, with roofing accessories, photovoltaic solutions or innovative materials for flat-roof membranes.

We also work across departments to develop innovations, monitor market trends and support wienerberger with the integration of acquisitions. In December 2022, for example, wienerberger announced its intention to buy selected core businesses of the Terreal Group, a successful European supplier of innovative roof and solar solutions. We are currently waiting for the approval of the competition authorities and the Closing. Once it has gone through, it will be the biggest acquisition in wienerberger’s more than 200-year history. This is a significant step for our company and an important strategic milestone on the way to expanding our position as the clear leader in the European pitched roof market.

On the subject of customer needs: What are customers looking for when putting up a new roof or renovating an existing one and how do you meet their expectations?

Reingruber: First and foremost, they want ease of use. So, we want to make it as simple as possible for our target groups (from roofers and builders’ merchants to end customers) to find and install the solution that fits their needs. In recent years, we have therefore systematically expanded our product range. Today, we offer country-specific complete solutions: starting with roof tiles and ceramic accessories, through a full range of technical accessories such as skylights, underlays and storm clips to the very latest photovoltaic systems. In addition, we also offer useful services such as calculation programs and visualization tools. 

What developments and trends can you currently see in the roofing sector?

Reingruber: There is no doubt that pitched roofs have become popular again in recent years. Besides their basic function of providing protection from weather, roofs can also be used for a variety of other purposes, and it is these that are now increasingly coming to the fore – for example, more and more customers want to use their house roofs to produce solar power. Equally important is the collection, storage and recycling of rainwater. By combining roof and storage solutions, wienerberger is able to offer excellent complete systems for this purpose. 

wienerberger has a strong focus on innovative, ecological solutions for the entire building envelop. What does the extremely durable clay roof tile contribute here?

Reingruber: Our mission is to provide high quality, innovative and sustainable roof systems. The clay roof tile is central to this – it is a highly durable product that has been around for thousands of years, and we are constantly working to make it even better. Across its entire lifecycle, this natural product is significantly more sustainable in its use of resources than other materials: fired at extremely high temperatures, clay tiles can achieve a lifespan of more than 100 years. One interesting fact in this context: Studies of the roof tiles of the Dominican Church in Krems in Lower Austria, showed that they date back to around 1330 – so they have been protecting the church roof for almost 700 years! 

What challenges need to be overcome, especially in connection with ecological solutions?

Reingruber: The constant changes to the legal requirements in terms of ESG, both at national and EU level definitely present challenges. They are not always easy to implement in practice. Let me give you one example: The European Commission is revising its Building Directive to oblige homeowners to carry out certain renovations. Under the new rules, residential buildings would have to achieve an energy efficiency rating of at least D by 2033. However, this requires investments that are not always economically viable. This is why subsidies are needed to increase the energy efficiency of buildings.

“A combination of thermal insulation and roof tiles can significantly reduce a building’s energy consumption – both for heating in winter and cooling in summer.”

Christian Reingruber

Christian Reingruber

Chief Strategy Officer (CSO) Roof Solutions and Applications, wienerberger

New buildings are already planned to be energy efficient. Due to new building regulations and subsidies as well as higher energy prices there is growing interest in energy efficiency, including the renewal and renovation of roofs. What potential do you see here?

Reingruber: Since buildings account for approximately 40 percent of energy consumption in the European Union, there is enormous potential for the renovation and refurbishment of real estate. In fact, this segment is the fastest growing market for wienerberger. With our products we are part of the solution and are helping to advance sustainable living.

Renovation has always accounted for a large part of wienerberger’s revenues in the roof segment and it will continue to play a key role in the future. Thermal rehabilitation is often the top priority because typically about 20 percent of heat is lost through uninsulated roofs. It therefore makes a lot of sense to invest in thermal insulation in combination with roof tiles. This solution can significantly reduce a building’s energy consumption – both for heating in winter and cooling in summer. At the same time, building owners have the additional option of installing photovoltaic solutions, either to generate electricity for their own needs or to feed it into the power grid. 

Flat-roof membrane with up to 75 percent recycled content: wienerberger is contributing to the sustainability of flat roofs with its Leadax Roov System.

Flat-roof membrane with up to 75 percent recycled content: wienerberger is contributing to the sustainability of flat roofs with its Leadax Roov System.

From storms to torrential rain and heatwaves: Modern roofs should also help build resilience to climate change and extreme weather events. How do you meet these challenges?

Reingruber: The function of a roof as protection against the weather plays a key role – especially in light of the extreme weather conditions resulting from climate change. Roof tiles made of clay or concrete, for example, are significantly more hail resistant than other roofing materials. And to cope with storms, we have developed a matching storm clip for every single roof tile model.

wienerberger works continuously on product development to improve the protection function of roofs and also their usefulness for other purposes – for example, for more climate resilient buildings. For instance, we offer a white flat-roof membrane made of recycled plastic that can be completely recycled again at the end of its life. Just like light-colored roof tiles, it is optimized to provide a strong sun reflection effect and so heats up less during hot spells, which in turn significantly reduces the temperature in the surrounding area. It is an excellent base for green roofs that provide an additional layer of insulation against heat and cold. 

What role can roofs play in water conservation and biodiversity?

Reingruber: Climate change is putting increased pressure on global water resources and biodiversity is also declining. Flat roofs with greenery or nest roof tiles for birds and bats on pitched roofs create additional habitats. Here we work very closely with one another in the wienerberger group. Rainwater, for example, can be collected from the roof with the rainwater management system from Pipelife and then used for the building. Roofs constitute large surface areas and can make a significant contribution in many respects – from rainwater management and encouraging biodiversity to power generation and protection from heat and cold. 

The EU has set a renewable energy target for 2030 of at least 32 percent. The expansion of solar power will play a major role here. What photovoltaic solutions does wienerberger offer for roofs?

Reingruber: We have an in-roof photovoltaic solution that is marketed under the Wevolt brand. It consists of solar panels that are integrated into the roof and blend harmoniously with the ceramic roof tiles. For our on-roof photovoltaic solutions in Austria, we also have special mounting systems that guarantee optimum weather tightness on the roof. The premium option is our solar roof tile. As the name indicates, the photovoltaic cells are integrated into the roof tile, thus preserving the aesthetic character of ceramic tiles. These solutions are ideal for complex roof shapes, as they make better use of the surface area and so provide greater capacity.

house with solar roof tiles
© Wienerberger B.V.
house with solar roof tiles
© Wienerberger B.V.

Detail view: The innovative Wevolt X-Roof system integrates solar modules into the roof surface.

As part of its efforts to promote circularity, wienerberger relies on recycled, recyclable and reusable solutions? What are your current goals in the roof sector?

Reingruber: Roof tiles are extremely durable products. In western Europe in particular, there is strong demand for used tiles for roof renovations as they blend harmoniously into the roof landscape. At the same time, our product developers make sure that all our products are 100 percent recyclable. As clay is a natural material, tiles that have reached the end of their service life and waste from the production process can be used in a variety of ways as recycling material: for example, as substrate for green roofs, or ground to sand for use on tennis courts or in our production processes as a substitute for aggregates such as clay or cement. We are working to gradually increase the share of recyclable material in our production. 

And finally, can we take a peep into the future: What role should roofs play in our lives in the future? 

Reingruber: The motto “From protection to multi-function” describes it best for me. Both these characteristics are important. In the past, the focus was quite clearly on providing protection. In future, however, we will make roofs even more useful. Usable space is limited and is becoming increasingly valuable, not just in urban areas. We therefore have to make the best possible use of roofs – for example, for photovoltaic systems, greenery and for collecting and storing water.

“In future, however, we will make roofs even more useful. Usable space is limited and is becoming increasingly valuable, not just in urban areas.”

Christian Reingruber

Christian Reingruber

Chief Strategy Officer (CSO) Roof Solutions and Applications, wienerberger

About Christian Reingruber

Christian Reingruber is Chief Strategy Officer (CSO) Roof Solutions and Applications at wienerberger. In this function, he has been responsible for the strategic direction of the roof segment with a focus on high-quality, innovative and sustainable roof systems and solutions since July 2023. After obtaining his Master’s degree in Banking and Finance, Christian Reingruber worked at an investment bank in London. He joined the world of wienerberger in 2005 and since then has held a variety of management positions within the company.

Learn more about wienerberger

Meadow, Trees, Green, Girl, water © Robert Staudinger

How we Live ESG at wienerberger

Cut emissions, recycle products, help others: wienerberger has ambitious environmental, social, and corporate governance goals.
two men working on a robot in a factory

How we create innovations for tomorrow

From climate-neutral bricks to rainwater management: wienerberger develops innovative products and solutions for the construction industry of the future.
bright roof, blue sky © Wienerberger

Climate Change: Getting Roofs Fit for Heat and Storms

From heat to storms: Climate change means roofs have to withstand increasingly extreme weather conditions. New approaches from wienerberger show how they do it.