Jane Henley, Senior Advisor, U.S. Green Building Council

Developing a scalable, financially viable model for the transformation of our global built environment is a crucial component of the climate change puzzle. Due to the outsized impact that the building sector has on climate change, zero-energy buildings hold enormous potential in terms of limiting greenhouse gas emissions and reducing our reliance on centralized energy grids. ZEB requires us to integrate the systems of energy, buildings, storage, generation and distribution to get maximum benefit.

As we increase our focus on carbon reduction, we must be mindful that our single-minded focus on energy, does not trade off against broader goals that drive the future proofing of our building stock. A sustainable ZEB building means that factors such as human health, water and transport are not forgotten in our quest to reduce carbon. As we slowly transform our built environment, building codes and voluntary rating systems such as LEED and CASBEE need to continue emphasizing these larger principles of integrated design.

Amory B. Lovins, Cofounder and Chief Scientist, Rocky Mountain Institute

Zero- or net-positive-energy buildings are increasingly required by law, policy, prudence, or customer demand. Using building-integrated, add-on, or nearby photovoltaics or other electricity sources, thermally passive buildings can achieve attractively low cost if they are designed or retrofitted to be very energy-efficient. A novel design method called “integrative design” (http://tinyurl.com/ndkx4hy and http://tinyurl.com/nlr7hsj) has proven in >1,000 buildings the ability to make very large energy savings often cost less than small or no savings. This entails optimizing buildings as whole systems for multiple benefits; using radical efficiency to shrink or eliminate HVAC systems whose saved capex buys the efficiency; starting savings downstream; doing the right steps in the right order at the right time; and counting costs by the building, not by the component. This approach has yielded ~90–100% HVAC savings in climates from tropical to subarctic at roughly zero marginal cost. Integrative design’s many obstacles are convertible into business opportunities, but this requires leadership, diplomacy, patience, and meticulous attention to detail.