Around the world, engineers, architects and policymakers have been exploring ways to deliver highly efficient buildings whose reduced energy demand is satisfied by clean, renewable energy. Building off of the broader concept of a green or sustainable building, the concept of the “net zero building” focuses on the energy dynamics and performance of the building. And as policymakers and leaders align toward the net zero concept, the focus on achieving deep energy efficiency has centered on integrated technologies as well as ways to connect buildings to the natural environment. Lessons learned from early efforts can help to inform the next generation of best practices. Early projects demonstrate that net zero energy buildings (NZEBs) are feasible and potentially economical even in the shorter term. However in each case, the project developers have faced a number of challenges, invoking some skepticism and uncertainty around the nearly/net zero energy concept. Based on interviews with representatives from over a dozen project implementers,1 three commonly cited challenges include: • Processes and transactions costs • The level of technology awareness • The engagement of building occupants This paper considers both the direct and indirect experiences of project developers, key stakeholders and policymakers involved in net zero energy construction and major retrofit activities in commercial and public-sector buildings. The findings of this research are intended for, among others, commercial and public building managers and decision-makers seeking to optimize cost and resource efficiency (energy, water and waste) as part of long-term building asset management strategies.