Abstract
This report has been developed in RetroKit,a project where 11 countries collaborate in developing prefabricated solutionsfor retrofitting multifamily buildings from 1945 to 1980. This building type hasa huge energy-saving potential, consuming 68% of the total final energy use inbuildings in Europe. The type of buildings share common features across theEuropean borders, making them suitable for retrofitting with prefabricatedmodules. To develop good solutions this projectseeks knowledge on the needs and views of the stakeholders involved inretrofitting in the 11 countries through a questionnaire survey. The survey showswhat requirements prefabricated retrofit solutions must offer to be attractive:energy performance, adaptability to the building, efficient construction, flexibledesign, and adaptability to the resident's needs. Most referencedcharacteristics of good retrofitting design are energy efficiency, cost andaesthetics. The greatest pitfalls associated with prefabrication are limitedarchitectural freedom and poor architecture.