Why district hea­ting alo­ne is not en­ough - and heat pumps in exis­ting buil­dings must de­li­ver now

In the context of an article in the Frankfurter Allgemeine Zeitung from 24.06.2025 on district heating – with price increases of up to 30 % in major cities such as Hamburg or Frankfurt – a clear focus on decentralized heat pumps as an effective supplement can be derived from a technical and economic perspective. Although district heating remains an important model in densely built-up metropolitan areas, it brings with it infrastructural, regulatory and economic challenges. A certain systemic risk remains recognizable: district heating is increasingly sinking into a monopoly situation - with non-transparent tariffs and sometimes sharp price increases.

Grid expansion is expensive, slow and highly complex

The expansion of district heating is considered a central pillar of the heating transition - but only where the infrastructure and building density justify the expense. According to the Prognos study, over 43 billion euros in investment will be required by 2030 alone to expand and decarbonize existing district heating networks. Added to this are high civil engineering costs, lengthy approval processes, a lack of skilled trade capacities and planning uncertainties at municipal level. Another factor is that the construction sites required for the expansion will put a strain on residents and traffic for a long time to come.

A typical grid expansion takes several years – too long to meet the 2030 climate targets or the obligations arising from municipal heating planning.

Decentralized heat pump solutions such as PAUL Net Zero completely bypass this hurdle:

• They require no connection to overloaded grids and no upfront infrastructural work.
• Instead, they are installed directly on the building – quickly, scalably and independently of civil engineering and local authorities.

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Climate neutrality must not be postponed until 2045

While district heating theoretically has the potential to become CO₂-neutral, for the most part it is not yet. According to current data, the proportion of renewable energies in district heating networks in Germany is only around 20% – in many regions, significantly less. Fossil fuels such as natural gas or coal continue to dominate, even in newer networks. The political ambition is clear: the heat supply must be climate-neutral by 2045 – but what will happen by then?

This is exactly where PAUL Net Zero comes in:

• Heat pumps in combination with photovoltaic electricity and AI-controlled heating control are already enabling a CO₂-free supply in existing buildings.
• This immediately improves the carbon footprint, reduces emissions and helps cities and municipalities to meet their interim targets – not in 20 years' time, but immediately.

District heating is localized - heat pumps are flexible

District heating works well when there is a high connection density, short distances and central generation structures – i.e. primarily in dense urban areas or in new-build districts. In rural regions, commercial areas with heterogeneous development or fragmented existing structures, it is often not technically or economically feasible.

Particularly in Germany, where many municipalities have a small-scale building structure, it is not possible to achieve a comprehensive supply of central heating.

Heat pump solutions such as PAUL Net Zero, on the other hand, can be used across the board:

• Whether an old building from the 1950s, a post-war housing estate or a mixed neighbourhood – the intelligent combination of heat pump, smart network hardware and digital balancing means that even difficult stock can be decarbonized.
• Without demolition, without renovation, without compulsory connection.

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District heating is expensive and often monopolistic - heat pumps create price transparency

Price developments in existing district heating networks are an often underestimated risk. These are often subject to monopoly structures, as there is no choice of supplier. The result: high price increases, as recently seen in Frankfurt or Hamburg with +30 % within one year. Price indices are often based on fossil fuel suppliers and remain opaque for consumers.

PAUL Net Zero takes a different approach:

• By using local photovoltaic electricity, efficient consumption via hydraulically balanced heating systems and an AI-regulated control system, ongoing operating costs are noticeably reduced.
• The pricing policy is linked to transparent indices (electricity and heating price index) - and is cheaper than local district heating. At the same time, there is no investment risk as the model is completely contracting-based.

District heating remains a relevant component of the heating transition - but not a panacea

Decentralized heat pump solutions such as PAUL Net Zero are a technological, economical and socially acceptable addition, especially where central supply reaches its limits. They enable the immediate decarbonization of existing buildings - without full refurbishment, without infrastructure obstacles, without long planning times and permanent annoyance for residents and traffic.

Let's talk about PAUL Net Zero – get in touch now