Municipal heat planning with GIS

A heat plan starts with each building

Germany’s Heat Planning Act (Wärmeplanungsgesetz, WPG) requires every municipality to plan its heat supply. Cities with more than 100,000 residents had to present their heat plan by mid-2026. All other municipalities have until mid-2028. The goal is a greenhouse gas neutral heat supply by 2045.

The question a heat plan has to answer is a spatial one. In which streets and districts does a district heating network make sense, and where will each building keep its own heating? The answer depends on data that, in most municipalities, sits in different places. Heat demand is in state studies or consumption records, energy sources are in the census, and the gas and heating networks are with the municipal utility. Building age and renovation status are often not recorded completely anywhere.

A GIS brings this data together on one map, for every building and every block. A dashboard for Rheinbach in our gallery shows what that looks like. It maps the heat demand of all 14,961 heated buildings, the streets and blocks where demand is highest, the main energy source per block, and the buildings where a retrofit would have the most effect. The data comes from the open Energieatlas NRW and the Wärmestudie NRW.

How heat planning works

It starts with a status analysis. In Mainburg, where we are preparing the heat plan with a partner, we brought together heat consumption density, the share of each energy source, building types, renovation status and the gas and district heating networks. Energy sources come from the 2022 census. A digital twin of the town is the shared data foundation for every step that follows.

The potential analysis looks at where energy can be saved, which renewable energy and waste heat are available locally, and which areas are suitable for a district heating network. Where none is suitable, heating each building separately remains the better option. The result is a target scenario for 2045 and a catalogue of measures. In Mainburg, each measure has a profile with its costs, funding options and climate protection potential.

For a single district, an energy district concept goes into more detail. In the Luitpoldhöhe redevelopment area in Amberg, we recorded renovation status and building age classes on site and built a heat atlas from them. Each measure in the catalogue was assessed for cost-effectiveness, security of supply, social acceptability and ecological effect. In Altrip, we also assessed a district heating network and developed a concept for controlling and monitoring.

Measures only happen if people in the municipality accept them. In Mainburg, that meant public events and workshops; in Amberg, close work with the municipal utility. In all three projects, we delivered the results as a WebGIS that runs in the browser. In Mainburg, it also makes the results accessible to residents.

Heat planning in GOAT

In GOAT, you upload your own data, such as buildings with heat demand or the utility’s networks, and add buildings, settlement structure or population from the Catalog. All layers sit together in one project.

You build the analysis as a Workflow. For Bedburg, a workflow uses SQL queries to sum up the heat demand of buildings and the solar potential of rooftops per block, saves the result as a dataset and adds it to the project. The priority zones for solar expansion come from that result. When the data or the boundaries change, you run the same workflow again. The GOAT documentation explains how workflows are set up.

To present the results, you build a Dashboard with key figures and charts next to the map. In Rheinbach, clicking a building shows its heat demand in a custom Popup, and a chart shows how urgent retrofits are in each block. With Share, you publish the dashboard so it opens without a GOAT account. The documentation also covers how to build a dashboard.

You can open both examples in our gallery: heat planning in Rheinbach and solar potential and energy demand in Bedburg.

You can run the analysis yourself in GOAT, or work on your heat plan with us. The projects are listed directly below.