When Photovoltaics become part of the roof covering

How the Energiedach Combines Photovoltaics and Roof Covering into a Rainproof System

By Paul Zielinski, Head of Technical Consulting and Roof Product Support,
and Bianca Marklstorfer, Marketing

Munich, June 2026. Right in the heart of Munich, just a few steps from Leopoldstraße, a residential and commercial building was extended by an additional storey and upgraded for energy efficiency. The owners wanted to generate solar power without changing the building's understated roof appearance. The building's protected architectural ensemble status also imposed strict design requirements. The solution was a system that combines photovoltaics and roof covering into one functional unit: the ERLUS Energiedach.

The extension required a completely new roof structure. The timber construction was planned and erected by Zimmerei und Holzbau GmbH Frank from Munich. The main challenges of this inner-city construction project, with its small courtyard, were planning, site setup and close coordination between the different trades. Following a laser-based 3D survey, the timber construction company digitally planned the structure and prefabricated the timber components.

The new roof structure was then built. Master carpenter and state-certified timber construction technician Stefan Frank sees the main advantages of the Energiedach in its installation: “We didn't need any additional components for the Energiedach – it's very installer-friendly. Four-centimetre counter battens not only help keep the PV modules cooler, but also reduce the moisture content of the roof battens. That's why we use them as standard in our roof structures,” says Frank. The roof structure was completed using 60 mm wood fibre insulation boards, a bonded, vapour-permeable roofing underlay (UDB eA) of Class 2 and counter batten sealing strips, in accordance with the manufacturer's specifications.

First Munich Project Featuring the Energiedach

Roofing and sheet metal contractor Pesl from Munich then took over the remaining work on the roof. For guild member and managing director Michael Pesl, the customer's requirements were the top priority: “The integrated appearance and ease of installation were decisive factors. Especially with a roof pitch of just ten degrees, the system was a very good fit for the building and easy to install,” says Michael Pesl.

His project in the Bavarian capital was one of the first in Germany to feature the ERLUS Energiedach. “What is particularly interesting for us roofers is that we install the entire roof covering, including the PV system. The electrician then only needs to carry out the work inside the building.” This means that the core expertise of roofing – including the entire use of the roof, such as daylighting, energy generation, safety measures against snow and protection against wind uplift – remains in the hands of one specialist trade.

The four-storey building in Munich was completely extended by an additional storey. The new level was constructed with relatively few supporting columns by using four timber-steel beams. The pitched roof has a 45-degree slope along the window façade and a shallow 10-degree pitch across the large roof area. The new level accommodates office spaces with a continuous south-facing window façade and several dormers, as well as a balcony and roof terrace. The extension therefore required a complete roof renovation.

Installation Similar to Conventional Roof Tiling

The roof areas with a pitch of just 10 degrees were ideally suited to ERLUS Level RS with its triple ring interlocking, as this roof tile has been proven to provide rain protection even at such a low roof pitch. For power generation, the ERLUS Energiedach PV system, precisely matched to the Level RS, was the ideal solution. A total of 78 Energiedach modules, arranged in two module strings, fitted onto the south-facing side of the gable roof. Framed by Level RS roof tiles, the PV system blends harmoniously into the overall roof appearance. This is made possible by the Energiedach's special design. “We practically installed the modules just like roof tiles,” reports master roofer Markus Schmelzer. Together with two employees, he measured, installed and wired all 78 modules in just one working day. “One module replaces around six and a half roof tiles. That saves a considerable amount of time. The integrated wind uplift hook on the module also provides maximum protection against wind uplift while making installation extremely straightforward. The Energiedach is secured using conventional sheet metal screws and the same storm clips as the roof tiles.”

Wind Uplift Resistance and Hail Protection

Each individual Energiedach module is secured with a storm clip and eight screws. In addition, the module's “finger” – its wind uplift hook – engages underneath the adjacent clipped roof tile or Energiedach module, ensuring optimal anchoring against tensile and uplift forces. Roof tiles and modules are fully coordinated. “We didn't just want to create an appearance that matched the Level RS. We developed a system that is easy to install and allows for clean, professional workmanship,” says Paul Zielinski, Head of Technical Consulting and Roof Product Support at ERLUS.

For customers who value an aesthetically pleasing roof while wanting to integrate PV, the ERLUS Energiedach provides a photovoltaic system that performs the function of the roof covering while generating electricity at the same time. With a module weight of around 10 kg, triple ring interlocking, certified hail resistance class 4 and a high-quality aluminium finish, the Energiedach also features the same distinctive angular appearance as the Level RS roof tile.

Roof Covering and PV as One System

Unlike many conventional in-roof systems, the ERLUS Energiedach simultaneously performs the function of the roof covering. For this reason, the technically correct term is a roof tile replacement module rather than an in-roof module. “The Energiedach is a clean and attractive solution.

The well-designed construction and the simple series connection of the modules have really impressed me,” says master roofer Markus Schmelzer. The geometry adopted from the roof tile, with triple head and side interlocking, ensures reliable rain protection tested in accordance with EN 15601. As a result, the Energiedach provides the same level of rain protection as the Level RS roof tile covering, even at low roof pitches.

New Perspectives for Rooftop Photovoltaics

The Munich project illustrates a growing trend in pitched roofing: photovoltaics are increasingly becoming part of the roof covering rather than simply being mounted on top of it. This opens up new opportunities for the use of renewable energy, particularly in architecturally demanding buildings or in areas subject to ensemble protection and heritage conservation requirements.

Project Information

Roof tile: Level RS

In-roof photovoltaics: Energiedach for Level RS

Roofing and sheet metal work: Dachdeckerei und Spenglerei Pesl, Munich

Roof structure for building extension: Zimmerei und Holzbau GmbH Frank, Munich

You can download the project report including image material here.