The “Drei Prozent Plus – Umsetzung des energieeffizienten Sanierungsfahrplans für kommunale Quartiere” is a continuation of the earlier “Drei Prozent Projekt – Energieeffizienter Sanierungsfahrplan für kommunale Quartiere 2050” and was funded by the German Federal Ministry of Education and Research (BMWK, Förderkennzeichen 03ET4017B). The consortium is divided into three sub‑projects: A, “Erfahrungsaustausch und Beratungsnetzwerke” (DV); B, “Planungs‑ und Finanzierungstools” (HFT); and C, “Umsetzung Sanierungsfahrpläne und operative Methodik” (BSU). The project ran over a three‑year period, building on the conceptual work of its predecessor to test and refine digital instruments for the practical implementation of energy‑efficient renovation plans in municipal districts.
The technical core of the effort lies in the development and deployment of several digital tools. The CrowdSourcing Tool (CS‑Tool) allows private owners to upload basic building data through a user‑friendly interface (WEG‑Tool). The uploaded data are then processed by the CS‑Tool, which visualises the building’s energy demand for electricity, heating, and cooling on a monthly basis and estimates the potential photovoltaic (PV) generation and associated costs. For example, the dashboard for a single‑family house displays a monthly PV potential of up to 3.5 kWp and a corresponding cost estimate of €1,200 per year, while the heat and cooling demand curve shows a peak of 12 kWh per day in winter and 4 kWh per day in summer. The tool also compares the heat demand before and after a typical renovation measure, demonstrating a reduction of 30 % in annual heating energy, which meets the EU‑Taxonomy requirement for a 30 % energy savings in building renovations.
The BuildingScout portal (AP 4.2) extends the analysis to single buildings and small building groups. It integrates the SimStadt platform and the BuildingPhysicsLibraryEditor to generate building typologies and simulate various retrofit scenarios. The portal provides a graphical representation of the energy performance, cost, and payback period for each scenario, enabling stakeholders to compare options quickly. Data integration for success control (AP 4.3) links the results of the CS‑Tool and BuildingScout to a central database, allowing continuous monitoring of implemented measures and verification of energy savings against the planned targets.
The project also explored storage scenarios (AP 4.4), evaluating both centralised and decentralised battery solutions in terms of technical feasibility, cost, and grid impact. Finally, AP 5.5 focused on operator and financing models, developing product and business‑model concepts and financing solutions tailored to the needs of municipal authorities, owners, and utilities. The study identified that targeted financial incentives—such as a 90 % tax deduction over ten years for owner‑occupied dwellings and a 100 % deduction over twelve years for rented properties—significantly reduce the perceived barrier of financing, as confirmed by a survey of commercial owners who reported limited knowledge of the benefits of energy renovation.
The collaboration among DV, HFT, and BSU ensured that the tools were not only technically robust but also aligned with the practical needs of municipalities and their advisory networks. The project’s outputs include a suite of open‑source software, a comprehensive database of building performance data, and a set of financing templates that can be adapted by local governments. By combining user‑friendly data collection, advanced simulation, and evidence‑based financing mechanisms, the project delivers a scalable framework for accelerating the implementation of energy‑efficient renovation plans across German municipal districts.