The objective of this project is to address the issues described under “Background” by developing:  

  • Evidence of the practical feasibility and satisfactory operation of a range of installed retrofit systems in large non-domestic buildings in a number of countries, together with insights into the thinking that led to the choice of system. 
  • Simple to use, accessible advice to support the initial selection of system options for specific circumstances, signposted to evidence and summaries of the relative strengths of each option.


Climate goals require a major reduction of carbon emissions from existing and new buildings, both newly built and those that already exist. Existing non-domestic buildings are responsible for a substantial proportion of these emissions and are therefore increasingly a target for policy actions. As in other sectors, electrification of heating with heat pumps will be a major element of national and international policies, such as those recommended by the IEA.  

While the technical options that are available for retrofitting heat pumps to dwellings are also applicable to the numerous smaller non-domestic buildings, larger non-domestic buildings contain a variety of more complex heating, ventilation and cooling (HVAC) systems. These present different challenges and opportunities. In practice the retrofitting of heat pumps will often be part of more general refurbishment of a building. The scale and extent of anticipated refurbishment will be an important factor in determining which options for heat pump systems are technically or economically feasible. 

This complicated landscape is difficult to navigate and there is a need for straightforward, high-level guidance for building owners and other decision makers: they may know they need to take action but may not know what options are available, or how to choose between them. Decision makers will also be influenced by the availability or otherwise of evidence from similar existing buildings and systems to demonstrate feasibility and satisfactory performance. 

The design and operation of retrofit heat pump systems for large buildings has not previously been systematically explored by the HPT TCP, although Annexes 16, 30, 50, have explored options for dwellings and similar buildings and some aspects of systems for larger ones and the monitoring within Annex 52 includes some retrofit installations in larger buildings. EBC Annex 48 which deals with energy efficient retrofit of buildings is also pertinent. Relevant information from these studies will be reviewed and considered where necessary. 

Contact Person

Oliver Sutton oliver.sutton@beis.gov.uk

Mr. Roger Hitchin roger.hitchin@hotmail.com

Participating Countries

Austria, Italy, United Kingdom


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