Concepts for energy-efficient renovation at project level are often successful. However, later it turns out that scaling up of these concepts did not work. It is often unclear why not. We investigate what is still needed to scale up these concepts. The focus is on building/area scale and concepts that reduce grid congestion. By interviewing parties in the market and studying literature, we make a regional-temporal case study analysis. Case studies in: Utrecht, Amsterdam, Zwolle, Enschede, Zoetermeer, Hengelo, s Hertogenbosch. The results are: • Lessons learned • Societal and scientific follow-up questions • Advice for subsidy provider • Sharing knowledge