Berlin startup WALLROUND has secured an oversubscribed €4.2 million seed round to accelerate its mission of digitising and streamlining energy-efficient building renovations across Europe. The round was led by early-stage venture firm Revent, with participation from GGF and continued support from Vonovia, Europe’s largest landlord.

Founded in 2024, WALLROUND is building a full-stack renovation service that integrates property analysis, planning, procurement, construction and quality assurance on a single platform. The company aims to bring greater efficiency to a sector long criticised for outdated and fragmented processes, particularly in the renovation of residential portfolios held by landlords and institutional investors.

The fresh funding will support WALLROUND’s expansion across Germany, automation of planning workflows, and team growth in technology, operations and product development. The company has also set up an advisory board, joined by Kai Enders, former DACH CEO of Engel & Völkers, founder of GvFC Immobilien, and long-time president of the German Franchise Association.

Dr Lauren Lentz, General Partner at Revent, said: “We’ve watched the energy renovation space for a long time. But WALLROUND is the first team we’ve seen to combine an end-to-end tech solution with operational excellence. This is what the future of renovations looks like.”

With real estate owners under increasing pressure to reduce emissions, demand for energy-efficient upgrades continues to rise. However, renovation processes remain manual, slow and costly. WALLROUND’s digital platform is designed to simplify these projects, enabling landlords to decarbonise their assets while improving profitability and avoiding regulatory risks.

Lukas Steinhilber, CEO and Co-founder of WALLROUND, explained: “Our goal is to simplify renovations to the point that anyone can decarbonise their building – profitably. We’re not just offering a service; we’re building a scalable system that can meet the massive demand ahead.”

The company is focusing on private landlords and institutional investors, an underserved segment that collectively holds a significant share of Germany’s residential housing stock.

Friedrich Neuman, Partner at GGF, added: “Building renovation is an opportunity to create meaningful impact while building a massive business. WALLROUND’s vision to build Europe’s largest renovation franchise comes at a pivotal moment, helping landlords and investors avoid stranded assets. Their full-stack approach, with software at its core, unlocks significant efficiencies and sets the stage for WALLROUND to accelerate the built environment’s energy transition.”

Additional backers in this round include KVL Group, Founders Factory, S&B Capital, Micro-VC Superangels, and angel investor Marc Müller. With renovation becoming central to Europe’s decarbonisation drive, WALLROUND is positioning itself to lead with a scalable model that combines technology with on-the-ground delivery.