To accelerate deep energy efficiency retrofits, cities need better collaboration and international knowledge exchange. Strict building codes, energy labeling, and an innovative retrofit industry have made Denmark a world leader in energy efficiency. The historic CLCPA and LL97 climate laws put NYS and NYC at the forefront of the building retrofit industry. During this session, Danish and American specialists will exchange ideas on how to leverage building retrofits and public-private partnerships to support economic development and innovation. Through a series of fireside chats and case study presentations, the speakers will discuss topics such as the differences between doing business in Denmark versus New York, how to overcome the barriers of retrofitting buildings, and strategies to maximize the performance and benefits while minimizing costs.