A Roadmap to Net Zero Energy Commercial Buildings
Net zero energy buildings (NZEBs) are highly efficient, renewable energy fed buildings that generate as much or even more energy - in the form of heat, electricity, cooling, etc - as they consume. Making NZEBs a reality will require an average 60-70% reduction in building energy use, while maximizing natural heating, cooling and ventilating capacity. Such buildings will also likely require the use of technologies and designs that differ significantly from those in use today.
Developed by experts from within Johnson Controls in collaboration with the Institute for Building Efficiency (IBE), this issue brief provides a first look at what this transformation will require and is the basis for further work and analysis.
NZEBs represent a transformative shift in the built environment. Currently, buildings account for around 40% of primary energy consumption globally, emitting a similar percentage of worldwide greenhouse gas emissions. If a large share of global building emissions and energy use levels could be brought down to net zero levels, a number of worrying resource and ecosystem pressures could be mitigated substantially. Inspired by this potential, legislators in the United States (US) and in the European Union (EU) have agreed a set of targets for NZEBs for the coming decades:
US: net zero energy for all new commercial buildings by 2030;
EU: nearly1 zero energy by 2018 for all new public buildings, and by 2020 for all new buildings.
As the issue brief highlights, the technologies and innovations exist already to make these targets achievable. Complexities do surround the deployment of NZEBs at economy wide scale, however.
Experts convened by the IBE for a workshop on NZEBs in Brussels on 14 September 20112 pointed in particular to policy uncertainties: the basic definitions, boundary conditions, measurement metrics and other components for a robust NZEB regulatory framework are either incomplete or missing in most countries. In addition, barriers to technology integration, as well as cost and financing concerns, are important challenges that need to be addressed.
1 Agreed in 2009 and 2010 as part of the negotiations over the EU’s revised framework building efficiency law – the Energy Performance of Buildings Directive (EPBD) – the term ‘nearly’ reflects a political compromise agreed between supporters of net zero energy targets and proponents of a less ambitious target. While the precise definition of nearly zero will be established by individual EU countries over the course of the next year, in practice the term means that a small amount of non renewable energy use will be permitted in buildings carrying a nearly zero energy distinction.
2 The workshop featured representatives from the International Energy Agency (IEA), the European Commission, the Buildings Performance Institute Europe (BPIE), the Energy Efficient Buildings European Initiative (E2BA), the Climate Group and others.