Reduce heating costs and avoid CO2 emissions – without any refurbishment. Heating is the largest source of CO2 emissions in the building sector: In Europe alone, €90 billion in avoidable heating costs and 400 million tonnes of CO2 emissions are generated every year.

The conventional solution: building refurbishment – around €1 million for a 10-unit residential building and many months of lead time. Many housing companies simply cannot afford this.

cosy.green offers the faster, more affordable solution: Our software with a proprietary algorithm, our self-developed control device and smart thermostats on every radiator automatically optimise the heating system in real time. Until now, all of this had to be done manually and was not continuously optimised. The potential: up to 40% less heating energy. In 4 reference projects, we have already achieved savings of 25–29%.

Best of all: The annual service fee can be passed on as an operating cost and is lower than the tenants’ heating cost savings – resulting in lower overall service charges. Landlords increase the value of their properties, while tenants still save money.

With our subscription model and 10-year contracts, we generate recurring revenue. 3 paying customers with 50 residential units are already using our solution, and a further 5,000 units have been contractually agreed. With this financing round, we will connect around 1,000 units by the end of 2026 – and aim to reach profitability by the end of 2027.

cosy.green was founded by an experienced, interdisciplinary team that combines deep technical expertise with market and sales know-how. These areas of expertise complement each other to form a strong overall picture, held together by a shared vision of decarbonizing heating without waiting for comprehensive energy retrofits.

The team is complemented by an experienced advisory panel that brings additional expertise in the areas of real estate management, energy law, and investor relations.

cosy.green makes the existing heating system in residential buildings intelligent – entirely without structural intervention. Software with a proprietary algorithm, a self-developed control device and smart thermostats on every radiator automatically ensure that the heating system is optimally adjusted.

Housing companies benefit in multiple ways: They take action without refurbishment, comply with regulatory requirements such as hydraulic balancing, reduce CO2 charges and improve the energy efficiency class. This increases property value and enables higher rental income and better financing conditions.

In 4 reference projects, 25 - 29 % heating energy savings have already been achieved. Savings of up to 40% are fundamentally possible. With just 4 buildings in only one heating season, we have already avoided approximately 20 tonnes of CO2; that corresponds to the annual emissions of almost 5 single-family homes!

Tenants also benefit: Although the service fee, which can be allocated according to the German Operating Costs Ordinance, is passed on to tenants through ancillary costs, the heating cost savings are generally higher. Overall, ancillary costs therefore even decrease. Added to this is greater comfort through smart, easy-to-use thermostats with a familiar rotary control.

Nursing homes, senior living facilities and student residences can also use the solution. In the future, a tenant app and automated heating cost billing will complement the offering.

Most heating systems in German residential buildings do not operate optimally. The reason: inefficiently configured systems and a lack of alignment between the heat demand in the apartments and the heat supply in the boiler room. And where optimisation does take place, it is fragmented: Hydraulic balancing, for example, costs €5,000-10,000 for a building with ten units, cannot be passed on to tenants – and remains an isolated measure. Smart thermostats, on the other hand, do take residents’ behaviour into account, but they do not adjust the heating boiler accordingly.

cosy.green combines both – and more. Our algorithm treats the entire heating system as one unit: Thermostats, heating boiler, weather and usage behaviour are optimised together – in real time and self-learning, tailored to each building and its residents.

Our core innovation is the software. For integration into existing systems, we have also developed our own control device. This combination is difficult to copy: Only those who control both the apartments and the boiler room together can capture the data of the overall system – backed by two years of development work. A patent search was successful, and the patent application is planned for Q1 2027.

With cosy.green, we are addressing a market under immense pressure to act. 3 drivers are having an impact simultaneously: rising CO2 costs for landlords, increasing energy costs for tenants and stricter energy efficiency class requirements, which directly affect property values.

Since 2023, the Carbon Dioxide Cost Allocation Act has regulated how CO2 costs are divided between landlords and tenants: The poorer a building’s energy performance, the greater the share borne by the landlord – divided into 10 levels, with landlords of particularly inefficient buildings bearing up to 95%. Energy-related modernisation therefore has a direct economic impact on landlords.

Across Europe, around €90 billion in avoidable heating costs are incurred each year (€22 billion in Germany), of which approximately €22 billion relates to professional property owners (€7.5 billion in Germany). This segment is growing by around 12.6% annually. Our goal: Within 6 years, we aim to generate annual revenue of €20 million from this market. We are starting in Germany and then intend to expand gradually across Europe.

Our target customers are property companies with large residential portfolios. For them, heating costs, CO2 costs and regulatory requirements are not peripheral issues, but significant economic factors. cosy.green is therefore not merely a useful addition, but an economically essential tool.

The market for heating optimisation is fragmented: Many providers improve individual parts of the system – smart thermostats here, boiler control there. But individual measures cannot simply be added together: If they are uncoordinated, they address the same losses and their effects overlap. And some are expensive – hydraulic balancing costs €5,000-10,000 per ten-unit residential building. These are costs that the owner cannot pass on to the tenants.

cosy.green is the only solution that optimises the entire heating system – from the thermostats in the apartments to the boiler control in the basement – fully coordinated and fully automated. At the heart of the system is a self-developed algorithm: It combines weather forecasts with the actual heating demand of the residents, continuously calculates the optimal flow temperature for the heating system and adjusts it automatically. This keeps every apartment warm without wasting energy – reducing tenants’ heating costs and owners’ CO2 charges.

Because cosy.green controls both levels – the thermostats in the apartments and the heating system in the basement – hydraulic balancing can also be offered at the same time, without the additional costs mentioned above. In the future, heating cost billing is also intended to become part of the offering. Other providers are currently unable to deliver this independently and therefore attempt to achieve it through partnerships with one another. With cosy.green, everything comes from a single source.

The savings potential is up to 40%; 4 reference projects achieved 25 to 29%. In short: as simple and affordable as an individual measure, as effective as a refurbishment. The only alternative with a comparable effect is full refurbishment – at a multiple of the cost.

In addition, there is no upfront investment, fast installation without structural intervention and ten-year contracts that provide planning certainty for both sides. And the economics work: The cost of acquiring a customer is around 1% of the revenue that customer generates over the contract term.

A risk-free trial phase with agreed KPIs and a special termination right if they are not achieved reduces the entry barrier for our customers – ten-year contract terms are also not unusual for hardware in the housing sector, for example for smoke detectors.

Our supplier finances the hardware through a five-year lease – keeping our capital risk low. Our gross margin over ten years is 50-65%.

Two pricing tiers per apartment and year: Standard (€200-300) includes automatic heating optimisation, a tenant app and a landlord dashboard, while Premium (€300-400) will additionally include automated heating cost billing and a digital refurbishment advisor in the future.

Crucially, the ongoing service fee can be passed on to tenants as operating costs – and is significantly lower than the savings. An example: With annual heating costs of €1,200, a tenant household saves around €340 based on the 28% savings achieved and pays a fee of approximately €250. This leaves more than €90 per tenant household per year. The landlord modernises without placing an additional financial burden on tenants.

Sales are conducted directly to housing companies and through partners: Energy consultants and property management companies recommend the solution. Municipalities open doors – they pursue climate protection targets, own housing companies and act as role models. Industry associations and specialist media provide visibility.

Within a short period of time, cosy.green has successfully made the transition from prototype to market-ready product: 50 residential units are currently live, and 3 customers are already paying for our services, while contractual agreements are in place for a further 5,000 units. Annual recurring revenue has been growing continuously since the fourth quarter of 2025. Our customers include the City of Langenselbold, metis Verwaltungs GmbH and Benner Holding.

From the initial idea and successful pilot projects to market entry with tangible sales success, cosy.green has demonstrated that both the product and the business model resonate with our customers. In 2026, we plan to expand the digital tools for tradespeople, introduce a new dashboard for landlords and begin protecting our invention.

With this financing round, we are investing €600,000 in 3 areas: Operations (reliable processes, logistics, customer support), Sales and marketing (new sales partnerships, targeted customer acquisition, brand development) and Product development (application for tradespeople, dashboard for landlords, protection of our invention, certifications).

In the short term, we aim to achieve more than 100 contractually committed buildings by the end of 2026 and annual recurring revenue of €250,000 . In the medium term, the structured expansion to 5,000 units will enable us to operate profitably by the end of 2027 – and to develop from a technology pioneer into the market leader for heating optimisation in Germany.

No further financing rounds are planned before profitability: The current financial plan provides for the existing business model to become profitable from recurring revenue by the end of 2027. Additional rounds may follow for expansion into the European market.

1. Ready for the growth phase: The technical functionality and market demand have been proven. 5,000 units have already been contractually agreed, 3 paying customers trust us, and our revenue has been growing continuously since the end of 2025. The foundation for further expansion is in place.
2. The right time: Energy performance certificates directly influence the market value of properties. In Germany, landlords bear up to 95% of heating-related CO2 charges. The market for energy management systems in buildings is growing by an average of 12.6% per year. The regulatory and economic tailwinds have never been stronger.
3. Enormous market potential: €90 billion in avoidable heating costs in Europe, of which €22 billion relates to the addressed segment of professional property owners. For every € we invest in acquiring new customers, we generate one hundred times that amount over the entire customer relationship – the economics of our growth are exceptionally strong.
4. Experienced founding team: Sales and partnerships (15 years), software architecture (16 years), heating technology – research and development (4 years), building management systems (11 years) – all relevant areas of expertise are represented internally. The team has taken cosy.green from zero to its first customer revenue.

Building installation capacity. Our growth depends on how quickly and reliably we can equip buildings with our technology. We are therefore not building our own installation teams, but instead working with a network of regional heating technology specialists. This allows our installation capacity to grow with demand – without high fixed costs.

Long decision-making processes and dependence on major customers. In the housing sector, purchasing decisions often take many months, and individual large housing portfolios can have a significant impact on our business – at the same time, these major customers generate above-average order volumes per contract. We address this in two ways: through a structured sales process that guides prospective customers step by step from the initial conversation to the contract, and through three separate customer groups – municipal and cooperative housing companies, private owners of larger portfolios and property management companies. This distributes our revenue across several pillars.

Imitation by competitors. Our competitive advantage is based on 2 years of development work, a self-developed control device and a data set that combines thermostats and boiler control in one system – something no competitor currently offers. We have successfully completed a patent search, and the patent application is being prepared.

Hardware approval. Our control device requires European conformity marking (CE) under the Radio Equipment Directive. The process is underway and has been taken into account in our time and cost planning. We will only begin series production after successful certification – thereby avoiding misdirected investments.

Changes in legislation. Legal and tax frameworks may change and affect our business. So far, regulation has worked in our favour: The German Carbon Dioxide Cost Allocation Act requires landlords to contribute to the carbon dioxide costs of their buildings – anyone who reduces consumption saves directly. The key point, however, is that our offering is economically viable even without regulatory pressure because the heating cost savings are real.

The heating boiler in the basement does not know what is happening in the apartments above – causing Germany to waste billions every year. Based on this insight, Alex Hirsch founded cosy.green GmbH in Langenselbold in August 2024.

Today, a four-person team with expertise in physics, environmental engineering and systems development is behind the first system that connects radiators and the heating boiler – without refurbishment and without any investment required from the owner.

The first prototypes during the 2024/2025 heating season were followed by the first customers in 2025/2026; the reference projects have been completed: 25 to 29 percent savings and 5,000 residential units contractually agreed. By the end of 2030, we aim to make 24,000 residential units more efficient – in Germany and beyond.

Don’t buildings need to be refurbished anyway?

No – and that is precisely the point. Comprehensive refurbishment is expensive, takes a long time and often fails simply because of a shortage of skilled tradespeople. Heating optimisation, by contrast, is the improvement that can be achieved quickly: implemented rapidly, without dirt or noise and without tenants having to move out. It does not rule out future measures – quite the opposite: Even after the heating system has been replaced or the building has been insulated, our system ensures that the new technology can realise its full potential.

Can’t the technology simply be copied?

What makes our solution special is not a single component, but the way everything works together: We combine data from the apartments (thermostats) and control of the heating boiler in one system – to our knowledge, we are the only company to do so. This comprehensive data set is the result of two years of development work, together with our proprietary control device installed at the boiler, which is crucial to the quality of the control system. A patent search has shown that our approach is eligible for protection; the patent application is planned for next year. Anyone seeking to copy us would have to start this development from scratch – while we continue to collect additional operating data with every connected building and improve our system.

What happens if the owner replaces the heating system or installs a heat pump?

Our solution is not tied to a specific type of boiler. If the heating system is modernised, we adapt the connection of our control device to the new system. Heat pumps also benefit from our control system – especially so: They operate most efficiently at low flow temperatures, and that is precisely where our system excels. Replacing the heating system therefore does not terminate the contract, but is a normal adaptation scenario – and tends to make optimisation even more valuable.

Who is liable if there is a malfunction? What happens to the heating system warranty?

We do not interfere with the heating system itself – the warranty provided by the heating system manufacturer and installer therefore remains fully intact. If our system fails, the heating continues to operate as it would without us; residents are therefore not left without heat. We are responsible for our devices and software within the scope of the contract with the building owner; maintenance and replacement of defective devices are included in our all-inclusive service package. Responsibility for the heating system itself remains with the owner or the owner’s heating contractor, as before.

How secure is the data?

We process temperature and heating system operating data, not residents’ personal data. The measurements do not reveal who is doing what in an apartment. The data is transmitted in encrypted form via a low-power radio network specifically developed for such applications. We comply with European data protection rules and meet the European security requirements for connected products that have been mandatory since August 2025.

How do tenants benefit?

In three ways. First, heating costs are reduced – making tenants less dependent on fluctuating energy prices. Second, living comfort increases: Using a mobile application, residents can control their radiators remotely and set their own heating schedules – if they wish to do so; anyone who does not want to change anything does not have to, as the system operates in the background. Third, the application raises awareness of personal energy consumption. In the future, we also intend to process heating cost statements through the application – currently a major source of frustration for many landlords and tenants.

Why does cosy.green enter into ten-year contracts?

For three reasons. First: We provide the devices as part of the subscription – the owner does not have to provide any upfront capital, while the investment pays off for us over the contract term. Second: The savings are not a one-off effect, but are generated again year after year because our system continuously readjusts and is maintained. Third: Long-term contracts provide predictable, recurring revenue – for the company and therefore also for you as an investor.

What happens if the expected savings are not achieved in a building?

Every building is different, which is why we assess whether a property is suitable before entering into a contract – based on the type of heating system, consumption data and the condition of the building. After installation, we continuously measure consumption and can demonstrate the impact in clear figures. If a building falls short of expectations, we readjust the system; it learns from the operating data. An important point of context: The savings of 25 to 29% are actual measured results from our reference projects, not projections. The potential of up to 40% represents the technically achievable maximum, which we do not promise for every building.

When will cosy.green become profitable?

Our target is annual revenue of €250,000 by the end of 2026 and to reach profitability by the end of 2027. The foundation for this has already been contractually agreed: 5,000 apartments in the portfolios of our three customers are awaiting connection. The task is therefore not to create demand from scratch, but to convert existing contracts into recurring revenue.

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