12/17/2025

Ready for a heat pump? Online tool gives homeowners an initial assessment

Is my house suitable for heating with a heat pump? The new ‘Heat Pump Building Check’ provides homeowners with a quick assessment. Using a simplified room-by-room heating load analysis, the online tool shows whether the building is ‘low-temperature-compatible’, i.e. which rooms can be heated sufficiently with a flow temperature of maximum 55 °C or where this can be achieved with minor measures.

The ‘Heat Pump Building Check’ is a new, free online tool that is now available to homeowners to assess the technical suitability of existing buildings for the use of a heat pump. The application was developed on behalf of the Federal Environment Agency under the leadership of the ifeu Institute, together with the non-profit consulting firm co2online and the engineering firm Heckmann.

The 55-degree question: Is my house already suitable for a heat pump?

The tool answers a key question for many homeowners: Can my house be heated economically with a heat pump? This is not a problem if a heating flow temperature of 55 °C is sufficient to heat all rooms reliably and adequately on cold winter days. This value is considered an important prerequisite for the efficient use of heat pumps. The lower the flow temperature of the heating water in the radiators, the lower the energy required – and vice versa. In uninsulated old buildings, the flow temperature can be as high as 75 degrees, depending on the radiators. However, the flow temperature can often be significantly reduced by simply installing better radiators in individual rooms.

In the ‘Building Check Heat Pump’ tool, users enter some building data and record the relevant rooms. The tool then calculates the heat loss of the individual rooms and the heating output of the radiators. In addition, the check shows for each room whether adjustments are advisable and which ones are possible – such as better radiators or other efficiency measures.

More accurate than many online tools, easier than specialist planning software

With its room-by-room approach, the ‘Building Check Heat Pump’ closes the gap between simplified online tools at the building level and complex specialist planning software. It thus offers sound but easily accessible guidance for anyone planning to replace their heating system or prepare to modernise their building.

The ‘Building Check Heat Pump’ can be used free of charge. 

Start check (in German)