Cool Roof: Heat Protection Starts at the Roof

How the Level RS Cool Roof with its highly reflective
surface became part of a holistic climate concept

Aystetten, July 2026. A multi-generational residential complex comprising two interconnected semi-detached two-family houses is currently being built in Aystetten near Augsburg. A key element of the energy concept is the white Level RS Cool Roof tile from ERLUS. Its highly reflective surface is designed to reduce the heating of the building envelope and improve summer heat protection.

For the clients Erika and Alexander Graf, the project is a pilot project in many respects. Their aim is to build as future-proof as possible, with effective heat protection, healthy building materials, a sustainable energy concept, a high degree of flexibility and a high level of self-sufficiency. Since September 2025, two two-family houses with a shared underground car park and connecting building have been under construction. Even during the construction phase, the ensemble stands out in the local surroundings, particularly because of its white roof.

Climate change considered from the outset

“When we were planning the building structure, the increasing global warming was a major issue for us,” recalls Alexander Graf. Initially, the installation of a sophisticated air-conditioning system was also considered. As planning progressed, however, the team examined what contribution a highly reflective roof could make to reducing heat gain in summer. The decisive inspiration came from a project in France that Philipp Graf became aware of and which had been roofed with an ERLUS Cool Roof tile. This further strengthened the idea of building with climate considerations in mind. Ultimately, Erika and Alexander Graf decided against active air conditioning and instead opted for a combination of structural measures, with the white roof as a central element of the summer heat protection concept.

Summer heat protection as part of the overall concept

Based on their experience so far during the construction phase, the interior spaces heat up comparatively slowly even when outside temperatures are high. The Graf couple see this as confirmation of the chosen concept. At the same time, the need for complex climate control technology can be avoided. According to the clients, this results in savings in the high five-figure range.

Cool Roof reflects solar radiation

The Level RS Cool Roof features a highly reflective surface that reduces heat absorption. Measurements indicate a solar reflectance of 68.4 percent for the roof tile. As a result, the roof surface absorbs less radiant heat than darker roof coverings. The reduced heating of the roof can help keep interior spaces at a comfortable temperature for longer on hot days. Reduced cooling requirements can also have a positive effect on energy consumption and CO₂ emissions. In addition, the light-coloured surface supports the cooling of the building at night.

Heat protection for new builds and renovations

Michael Danner and his fellow carpenters from Holzbau Aumann have covered a total of 400 square metres of white roof surface with the Level RS Cool Roof for this project. Both roofs, with a pitch of 20 degrees, were already adapted to the structural dimensions of the angular Level RS during the prefabrication process, creating a calm, cohesive overall appearance centred on the roof ridge. “For highly insulated buildings, a reflective roof can be an interesting addition to summer heat protection,” says Michael Danner. The experienced carpenter also sees potential for this solution in roof renovations, particularly in urban environments.

How does the white surface develop over time?

The visual appearance of the roof surface is significantly influenced by environmental conditions. Factors such as air pollution, pollen or shading can encourage visible deposits. However, the precious engobe of the Level RS Cool Roof forms a closed surface that provides less opportunity for dirt to adhere than porous materials. During installation, particular attention was therefore also paid to clean cut edges and careful touch-ups using colour-matched cold engobe in order to maintain the overall appearance of the roof.

Architecture deliberately designed around the roof

The white roofs in Aystetten are the first in Germany to feature the ERLUS Level RS Cool Roof. According to those involved, the response from neighbours and the local community has been predominantly positive. At the same time, the roof also influenced the further architectural design of the project. “The Cool Roof has had a very positive impact on the overall appearance,” explains architect and civil engineer Matthäus Bleyer. “The windows are now finished in bronze, while the façade will feature a subtle cappuccino-coloured brushed render.” As planning progressed, the white roof developed into a defining design element of the entire ensemble. According to the clients and the architect, the buildings are intended to achieve a high degree of self-sufficiency. In addition to the planned photovoltaic system, this includes rainwater harvesting, highly insulated external building components and a building concept designed to minimise energy consumption. Completion of the multi-generational residential complex is planned for spring 2027.

PROJECT DETAILS

Project: New construction of two two-family houses with a shared underground car park and connecting building in Aystetten near Augsburg

Planned construction period: September 2025 to spring 2027

Architect: Matthäus Bleyer, Architect and Civil Engineer, Aystetten

Construction and carpentry: Holzbau Aumann, Ziemetshausen

Roof tile: ERLUS Level RS Cool Roof

You can find the project report for download, including image material, here. (Only available in German)