The building sector causes almost a third of the CO₂ emissions in Germany. Marcus Dietmann and Jörg Überla have joined forces to change that.
With the new heating law, which is to be passed in the Bundestag at the beginning of July, the traffic light government wants to accelerate the climate-friendly conversion of the building sector. This should be one of the decisive factors on the way to climate neutrality, because currently almost a third of the CO₂ emissions in this country are caused by the construction and use of buildings. However, with the new requirements, there is also an enormous financial and organizational effort for homeowners.
“That leads to a lot of frustration and uncertainty,” says Marcus Dietmann. In 2021, together with Jörg Überla, he founded the startup 42watt, which starts at exactly this point. The Munich-based company offers owners who want to energetically renovate their property independent and individual advice including a cost plan and accompanies them throughout the entire process. This should reduce the hurdles for a renovation.
Dietmann, a trained architect and energy efficiency expert, had the idea when he was looking for a new project that could combine sustainability with a successful business model, he explains in an interview in Gründerszene. His co-founder Überla, who previously helped build VC Wellington Partners and founded and sold a company himself, was actually supposed to join 42watt as a business angel. “But I found that so exciting that I said: I want to take part myself,” says Überla.
Advice from 42watt shows how much money a refurbishment saves
In their project, the founders see a “gigantic lever” for climate protection in Germany: On average, consumption of less than 42 kilowatt hours per year and square meter must be achieved in order to achieve the climate goals – hence the name of the startup. While new buildings are usually already below that, unrenovated buildings come up to 200 kilowatt hours. “So we will not be able to avoid decarbonizing all existing buildings,” explains Überla.
So far, this has been happening far too slowly, adds Dietmann. “The refurbishment rate would have to double, if not triple.” From an energy point of view, there is particularly large potential for savings in the conversion of the heating systems, from oil or gas to climate-friendly alternatives such as district heating or the much-discussed heat pump. “Climate protection is important,” emphasizes the expert, “but people only take action if it also makes economic sense.”
The advice from 42watt therefore also gives an outlook on possible savings through the renovation work. Two different products are available to customers for this: On the one hand, a state-subsidized renovation plan that is created on site by a certified energy efficiency expert. Here the state covers 80 percent of the costs, the customer pays a personal contribution of 395 euros. In return, there is a five percent discount on certain remedial measures if they are actually carried out.
Since this process is complex and there is also a lack of experts in many places, the founders have developed a free, digital scenario planner together with the Technical University of Munich. On the basis of a few data points and an algorithm, this calculates which measures would make sense for your own property, what they cost and when the investment will pay off.
Rapid growth is the most important goal for 42watt
Unlike other providers, the advice is independent of one’s own interests because 42watt does not carry out the renovations itself. “That’s one of our customers’ core needs and that’s what we deliver,” says Überla. The co-founder does not want to disclose how many homeowners the startup has already advised. However, since last summer, sales have “more than twelvefold,” he says. “Of course, this also affects a certain increase in personnel.”
In order to finance the expansion and development of the scenario planner, the startup completed a pre-seed round earlier this year, according to its own statements in the single-digit million range. The investors include the social VC fund BonVenture from Munich, Proptech1 Ventures from Berlin as well as Beate Fastich and Christoph Behn via the business angel club Better Ventures. McMakler boss Felix Jahn and founder and industry expert Kristofer Fichter have also joined as business angels.
The founders say that in the near future the startup will focus primarily on continuing to grow rapidly. “We’re still on day one when it comes to energy renovation,” says Dietmann, “there’s still a lot to do in the next two decades.” If they put their mind to it, the company could also become profitable “relatively quickly”, adds Überla. “But of course that doesn’t make sense when you’re in a market that’s currently exploding.” Instead, the aim is to eventually reach millions of households with your product. “We are building the company with this vision.”