The ProRetro project aims to - Overcome barriers to residential building refurbishment by offering new one-stop-shop services to customers in five German cities/regions - base the one-stop-shop design on the needs of customers so that - they are attractive to customers, - conceptualise, plan, implement and monitor and evaluate the new one-stop-shops - prepare their continuation beyond the project lifetime - cover the whole customer journey of a building renovation from audit/advice, planning, contracting, implementation and monitoring and approval – and involve respective stakeholders/experts in the service offer - build on information and experiences in designing and implementing one-stop shops from best practice examples in other European countries and establish peer-learning structures with those organisations