Würzburg, Germany, August 13, 2025. Whether for the fire station, city hall or multi-purpose hall – municipal properties will benefit from an energy optimization scheme recently launched in the German city of Würzburg. The aim is to make the city administration climate-neutral by 2028, and the entire city by 2040. One of the key considerations is to reduce carbon dioxide in the public building stock, which in the long term will save not only energy but also money. The city is working with a detailed refurbishment roadmap to ensure the energy upgrade project is a success despite the shortage of funds. For the first twenty public buildings, the plan recommends around 200 measures and highlights the potential for reductions in carbon dioxide emissions, the investment costs and the payback periods. Drees & Sommer SE specializes in advice on construction, real estate and infrastructure issues. The company’s expert teams have participated in the development of this roadmap for energy efficient modernization of the city’s public buildings.
Climate Killer: Slow Pace of Building Upgrades
As in many cities and municipalities, a large number of Würzburg’s buildings are ageing. Many of these were built in the 1960s and 1970s and are real energy guzzlers. The Lord Mayor of Würzburg, Martin Heilig, said: “Old windows, insufficient insulation and inefficient heating technology are putting a burden not only on the climate but also on the city budget, which is already tight.” However, in his view, energy upgrading is about far more than just cost-efficiency: “Our public buildings should be paragons of sustainability and inspire the city’s residents and businesses also to invest in energy upgrades. A climate-neutral city administration is therefore an important element in our climate action policy for the city as a whole,” the Lord Mayor added.
Roadmap for Refurbishment and Upgrading Shows the Way
The new refurbishment and upgrading roadmap takes a gradual approach to modernizing municipal properties over a period of 20 years. In line with the worst first principle, the city of Würzburg will first concentrate on the modernization of the 20 buildings with the highest energy consumption levels.
For this purpose, a priority ranking and recommendations have been drafted. Head pumps and photovoltaic systems are set to replace fossil energy sources. Improved insulation will make building operation more sustainable. “For each property, we have assessed the structural quality and energy efficiency, analyzed the potential for reducing energy demand and carbon dioxide emissions, and calculated the investment costs for repair, upgrading and replacement measures,“ said Moritz Decker, Drees & Sommer’s expert for climate neutrality and energy management. “On this basis, we have developed measures and applied criteria such as sustainability, efficiency and feasibility. The range spans from the installation of photovoltaic technology through the use of battery storage to the greening of roofs and façades,“ he added.
Upgrades Pay for Themselves
According to Mortiz Decker, the energy-related investment costs for the 20 properties investigated are in the region of 33 million euros. However, the city could save around a million euro per year in operating costs if the measures are implemented. This would mean the project could pay for itself in around 33 years. Martin Heilig commented: “In the long term, the project can pay for itself, whereas without the upgrades the city of Würzburg would face ever-increasing energy costs in the future. Also, by reducing carbon dioxide emissions by around 900 metric tons per year the upgrades would make a vital contribution to achieving the target of climate neutrality.”
Keeping an Eye on Capacities
To make the project cost effective, the city administration and Drees & Sommer have developed a ‘capacity-optimized roadmap’: our prioritization system is based not only on the condition of the relevant buildings, but also on Würzburg’s annual financial and staffing capacities,” explained Moritz Decker. For instance, the analysis takes into consideration when a property would be due for modernization under normal circumstances. “Technical equipment, installations and systems usually have an expected useful life of around fifteen to twenty years, while windows and glass façades have a lifespan of around 40 years. When these components come to the end of their useful lives, it is always advisable to replace them, from an ecological, economical and energetic perspective,” Moritz Decker continued.
Public Grants Reduce Initial Investment Costs
Besides the long-term measures, the refurbishment and upgrading roadmap includes several quick wins that can help to reduce consumption as well as energy costs in the short term.
Various energy upgrade promotion funds are available for the necessary investments, for instance for renovating buildings with the principal aim of improving the insulation; for replacing old oil and gas boilers; for installing heat pumps, for photovoltaic systems; or for switching to district heating based on renewables. There are also tax incentives such as special capital allowances. According to Moritz Decker, the German federal government and the individual federal states have to up their game in this area: “At less than one percent, the proportion of buildings undergoing renovation is far below the necessary three percent, so the grants currently available will not be sufficient to achieve the climate targets. Local authorities cannot bear the cost of the investments alone.“
Public Sector as a Role Model for Sustainability
Yet cities and local authorities play a major role in transforming the building stock. A recent study by the German Energy Agency (dena) found that the number of buildings being renovated and the extent of those refurbishments will have to be increased significantly, and around 120 billion euros of additional funds needs to be invested in the upgrading of public non-residential buildings by 2045.[1]
With this in mind, Würzburg’s refurbishment roadmap could provide a blueprint for other local authorities and demonstrate how systematic upgrading can be managed. “For successful implementation it is crucial that the city administration, residents and businesses all pull together. Climate action is a joint task that concerns us all and can only be tackled together,“ Lord Mayor Martin Heilig highlighted.
About the Refurbishment and Upgrading Roadmap for Public Municipal Properties:
In adopting the 2021 Integrated Climate Action Policy (iKK 2021) in 2022, Würzburg’s municipal council agreed to the target of achieving net zero greenhouse gas emissions for the city administration by 2028. In addition to setting up a municipal energy management system and adopting the Würzburg energy standard for municipal properties, one of the key elements of the 2021 integrated climate action policy for achieving Würzburg’s city administration’s target of overall climate neutrality is a roadmap for the upgrading of municipal properties. One of the specific requirements of the 2021 integrated climate action policy under the heading of city government is a roadmap for the creation of carbon-neutral buildings (‘worst first’) in order to develop, on this basis, an implementation and investment plan for the refurbishment of municipal properties.
An energy analysis was conducted to identify the potential for reducing the energy usage of the 20 properties with the highest heating consumption in the city of Würzburg (without schools) and to highlight steps that need to be taken to reduce carbon emissions.
The upgrading roadmap is the result of a close and constructive collaboration between all members of an interdisciplinary team formed by experts from Drees & Sommer SE and several specialists from the city administration.