Flat Roof Construction with System, Structure, and Foresight
Interview with Alexander Erba, Managing Director of Holl Flachdachbau GmbH & Co. KG Isolierungen
Holl Flachdachbau GmbH & Co. KG Isolierungen based in Fellbach specializes in flat roofs, lightning protection, and photovoltaics. As part of the Primutec Solutions Group, the company focuses on growth, acquisitions, and intelligent structures. In the interview, Managing Director Alexander Erba explains how technology, digitalization, and skilled labor retention can be interconnected – and why long-term perspectives in the crafts are crucial.
Wirtschaftsforum: Mr. Erba, how has your company historically developed and which steps were particularly significant?
Alexander Erba: Holl Flachdachbau GmbH & Co. KG was founded in 1965 – with a focus on flat roofing, which remains our core business to this day. In 1979, it was acquired by the Dutch Erdo Group. Since then, we have grown continuously through acquisitions, most recently in 2023 with the integration of the photovoltaic company Clen Solar. Our goal is to provide our customers with comprehensive roofing solutions – that is, roofing, PV, and lightning protection all from a single source. This one-stop-shop approach creates clear processes and coordinated responsibilities. We pursue a buy-and-build strategy: we grow organically through new employees and inorganically through acquisitions, which we integrate specifically into our structure. Today, we are part of the Primutec Solutions Group, operate 26 sites in Germany, and act as an operational single company as well as the German holding of the group.
Wirtschaftsforum: What is the current size of your company - both structurally and economically?
Alexander Erba: In Germany, we have around 800 employees working for us – predominantly in the flat roof segment, supplemented by experts from the fields of lightning protection and photovoltaics. Together with our Dutch sister companies, the group comprises about 1,400 employees. In 2024, our annual performance in Germany exceeded 170 million EUR, and across the group, it was around 370 million EUR. It's important to us to generate value ourselves – this ensures quality, speed, and reliability. At the same time, we consolidate central services like accounting, human resources, IT, or recruiting within a shared service structure. This relieves the burden on operational sites and creates economic and organizational efficiency.
Wirtschaftsforum: What do you see as the central challenges in the industry?
Alexander Erba: The demands in the skilled trades are increasing – technically, regulatorily, and personnel-wise. Smaller businesses quickly reach their limits. Issues such as the supply chain law, ESG standards, or documentation obligations are becoming almost unmanageable alone. Moreover, there is an increasing shortage of skilled workers. We address these challenges with a clear group structure, digitized processes, and targeted recruiting – including internationally. At the same time, we are working on innovations, such as an AI application for our construction managers, to reduce administrative burden. The market will continue to consolidate, and we are convinced that with our structure, we are well positioned for the long-term future.
Wirtschaftsforum: How long have you been with the company and how do you shape your role as managing director?
Alexander Erba: I have been part of the executive management since October 2023. My professional background is in real estate; I have worked in facility management among other areas. Together with my colleague Michael Leitz, I lead the group – he is responsible for the commercial aspects, and I take care of operational and strategic issues. I regularly visit our 26 locations. There, I accompany client appointments, assist in legal and project matters, and initiate strategic developments. My goal is to actively further develop the group – with a clear focus on market trends, customer requirements, and our organizational alignment.
Wirtschaftsforum: What specific initiatives have you already implemented – and where do you plan to continue?
Alexander Erba: One focus is on increasing the visibility of our group – many customers are familiar with individual brands, but not the overall structure. We are currently changing that in our external presentation. At the same time, we continue to drive digitalization – from internal processes to the introduction of the first AI applications. Additionally, there is a focus on employee development: We continue to specifically qualify and promote knowledge transfer between generations and build future-proof structures. Our goal is to retain experience within the company, integrate new talents, and jointly secure the long-term performance of our group.
Wirtschaftsforum: What does your current portfolio include, and how do the various service areas interact?
Alexander Erba: Our three core areas – flat roofing, lightning protection, and photovoltaics – are closely interlinked. Particularly because of legal requirements such as the mandatory photovoltaic installations, integrated consulting is crucial. We analyze when a roof should be renovated, how to economically integrate photovoltaics, and what lightning protection measures are necessary. Green roofing and retention roofs are also gaining importance. Additionally, we focus on white roofs, recycling materials, and the first circular insulation materials. We also offer facade solutions – including with PV, greenery as well as metal, glass, and special constructions. For large real estate companies, we develop comprehensive concepts, also with contracting or leasing models for flexible investment structuring. What distinguishes us is the combination of technical depth and practical implementation experience – we often accompany projects for several months, from planning to commissioning. Our customers value this reliable, partnership approach as well as the ability to solve complex requirements pragmatically. Our references include many well-known industrial and commercial clients, hotel chains, investors, housing companies, and data center operators.
Wirtschaftsforum: What role does communication play in your company?
Alexander Erba: Communication is central for us. In customer dialogue, we rely on personal consultation – ideally directly at the site. This allows us to precisely capture technical, economic, and timing aspects. Additionally, we utilize mailings and are expanding our presence on social media. Internally, we emphasize clear, reliable communication. An open feedback culture across all levels strengthens trust and quality – and thus customer satisfaction.
Wirtschaftsforum: What personally drives you in your role?
Alexander Erba: I have a passion for craftsmanship. It brings me joy to accompany demanding projects, create sustainable solutions, and further develop structures. It's not only about economic success but also about responsibility. My goal is a stable company that continues to provide secure jobs in 20, 50, or 100 years. For this, it is worth working every day with conviction and passion – together with a team that supports this path. That is my personal drive – to work every day with full conviction and passion.