Berlin-based proptech startup ecoworks has secured €5 million in seed funding for its climate-neutral approach to building modernisation. Surplus Invest led the round, with support from PropTech1 Ventures and wi venture, a German fund focused on sustainability. The proptech startup uses industrial prefabrication, digital processes, and energy systems to modernise multi-family houses with up to four floors within a few weeks. As a general contractor, ecoworks handles the refurbishment from beginning to end: submits building and funding applications, organises the modernisation project, and accompanies specialist companies on the building site. Once complete, the company becomes a heat service provider, supplying the buildings with clean energy for a period of 15 years. During the renovation process, the building is converted into “a small, decentralised power plant” by installing photovoltaic systems, heat pumps and thermal reservoirs. The modernised buildings will then generate more energy than the occupants consume for heating, hot water, and electricity. Any surplus energy goes into the public power grid. Projects are already underway in several German cities. The company hopes to expand quickly, citing that in Germany alone, there are around five million residential units built before 1978 which require modernisation. Commenting on the financing round, ecoworks co-founder Kristofer Fichtner said: "We are pleased that we have not only gained renowned investors, but thus also a wide range of diverse expertise.” A collection of angel investors, from within Berlin and within the sector, also participated in the round, including: Klaus Freiberg, former COO of Vonovia; SoundCloud founders Alexander Ljung and Eric Wahlforss; Christian Vollmann, founder of nebenan.de; Nicholas Neerpasch, founder of the building renovation platform Doozer; and Torben Schreiter, co-founder of Signavio, a product provider for business transformation based in Berlin.