ESCO stands for Energy Service COmpanies and is a public-private partnership (PPP) for achieving energy savings in buildings. The mindset in ESCO is simple; the resources, which are bound in a given property in the form of energy consumption, can be reduced, and the reduction of energy pays for renovation/optimisation of the property's energy-consuming installations and climate envelope.

The Danish Building and Property Agency enters into an energy partnership with a private ESCO partner, which conducts a thorough assessment of a given building and points out all the possibilities it finds for saving energy.

The unique feature of ESCO as a form of cooperation is that the private ESCO partner guarantees that the energy savings found will be performed and maintained. If the guaranteed cost savings are not achieved, the ESCO partner compensates for the missing energy savings, or carries out additional measures at its own expense in order to achieve the savings.

The ESCO system has been used with great success in other countries, such as USA, England and Sweden. Now it is about to gain a foothold in Denmark. The Danish Building and Property Agency has completed three ESCO projects; 2 in the Teilum building at the University of Copenhagen and one at Roskilde University. In addition, the University of Southern Denmark (SDU) has an ESCO project, which will be financed by SDU, and where SDU itself will be responsible for the guarantee instead of the supplier.