Innovation

The innovation behind GroenDak Service lies in Sem’s human-centered way of working. Unlike many competitors who deliver standardized green roof packages for self-installation, GroenDak Service offers a full-service, personalized experience. Sem personally visits each client to measure the roof, assess its structure, and explain the installation process in detail. This approach not only reassures customers but also ensures that each green roof is installed correctly and safely.

Rather than focusing only on the product, Sem places service at the core of his business model. He guides customers throughout the entire process and even assists with carrying materials onto the roof. This level of involvement builds trust and lowers the barrier for homeowners who may otherwise feel hesitant about sustainable investments. As a result, customers feel supported and confident in choosing a green roof.

Sem’s expertise is grounded in more than four years of experience working at SedumExtra, where he gained in-depth technical knowledge of green roofing systems. By combining professional expertise with an approachable, informal style, GroenDak Service delivers high-quality results while maintaining strong personal relationships. This service-driven innovation demonstrates how sustainability solutions can succeed when they are designed around people, not just products.

Inspiration

The inspiration for GroenDak Service comes directly from Sem’s personal journey. As a student of Entrepreneurship at Avans University of Applied Sciences, he wanted to build a business aligned with his interests, skills, and values. His work at SedumExtra, a supplier of green roof materials, gave him hands-on experience and sparked a deeper passion for sustainability.

Sem describes his work as more than a job. He is motivated by the combination of physical outdoor work, creativity, and the satisfaction of making customers happy. Creating something that is both functional and beautiful gives him energy, especially when clients respond positively to the final result.

The mindset of his colleagues and suppliers at SedumExtra also played a key role in inspiring him. Their shared belief, “We can do it. Let’s make it happen,” encouraged Sem to start his own business. This spirit shaped his professional yet personal approach and reinforced his belief that entrepreneurship can be a powerful tool for positive environmental impact.

Overall impact

Impact on customers

Customers experience immediate benefits after installing a green roof. Homes remain up to four degrees Celsius cooler in summer and retain more warmth in winter, reducing energy consumption and improving comfort. Many customers also express appreciation for Sem’s supportive presence throughout the process, which enhances trust and satisfaction.

Impact on cities and the environment

Green roofs deliver multiple environmental benefits. They increase biodiversity by attracting bees, butterflies, and insects, improve rainwater retention, reduce urban heat islands, and enhance air quality. To date, Sem has installed 333 square meters of green roofs. This is comparable to the annual environmental impact of approximately nine mature trees and offsets CO₂ emissions equivalent to about 700 kilometers of car travel. Each project contributes incrementally to greener, more resilient urban neighborhoods.

Impact on the entrepreneur

Sem’s personal and time-intensive approach requires commitment, but it has proven effective. Customers frequently recommend GroenDak Service to others, strengthening Sem’s reputation and creating steady growth. This trust-based model gives the business a clear competitive advantage while reinforcing Sem’s identity as a purpose-driven young entrepreneur.

Business benefit

GroenDak Service benefits directly from its service-driven innovation. Because customers feel personally supported, they show strong loyalty and actively recommend the business within their networks. Sem’s age also works as an advantage, as many customers are enthusiastic about supporting a young local entrepreneur.

Financially, the business is growing faster than expected. In 2024, Sem initially projected a turnover of €15,000 but achieved €25,000. Looking ahead, he envisions expanding the company with a small office, a professional work van, and a team of two or three employees. His long-term goal is to reach an annual revenue of approximately €100,000.

In addition, Sem is exploring opportunities in the B2B market, including partnerships with construction companies building houses or apartment complexes. Even a single large-scale client with extensive roof surfaces could significantly accelerate business growth compared to individual residential projects.

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Social and environmental benefit

Green roofs play a vital role in sustainable urban development. Through its installations, GroenDak Service contributes directly to:

SDG 11: Sustainable Cities and Communities

• Reducing heat stress in urban areas
• Increasing green infrastructure
• Enhancing neighbourhood liveability

SDG 13: Climate Action

• Lowering energy consumption through better insulation
• Reducing CO₂ emissions from heating and cooling
• Improving climate resilience in dense cities

SDG 15: Life on Land

• Supporting urban biodiversity
• Creating habitats for insects and plant life
• Restoring ecological balance in paved environments

Socially, customers feel proud to contribute to a greener city, and the personal relationships Sem builds foster trust and community engagement. His entrepreneurial journey also inspires others, especially young people, to see sustainability-focused entrepreneurship as a meaningful career path.

Interview

Sem De Leeuw, Owner