3 September 2018: The Buildings Energy Efficiency Task Group (BEET) of the International Partnership for Energy Efficiency Cooperation (IPEEC) published its seventh report on energy efficiency in the building sector, focusing on zero energy or zero emissions buildings (ZEBs). The report describes ZEB related definitions, leading ZEB policies and initiatives, lessons learned in policy implementation, and areas for further study.

Definitions

The document notes that harmonizing definitions and metrics used would lead to more uniform environmental impact. Through an analysis of the range of definitions used, the report finds, that: the most common metric is primary source energy; energy efficiency is usually a component of the definition, and a base level of energy efficiency is a common requirement; most EU definitions include a minimum renewable energy (RE) component but, contrary to US definitions, no “plug loads” (the energy used by means of an ordinary wall plug). The report also notes that similar definitions can have different impacts and that “zero carbon” is replacing “zero energy” as key metric, noting that additional research is required to understanding the impact of the two standards and their effects on policy.

Regional Analysis of ZEB Policies

EU policies require that by 2020 all new buildings and buildings occupied or owned by public authorities be “nearly ZEBs.” Each EU Member State must develop specific requirements of what constitutes a “nearly ZEB.” More than two-thirds of the EU Member States have in place policies for awareness raising and education, strengthening building regulation, and energy performance. The EU has also used financial instruments and support measures for ZEB promotion, including incentive policies, loans with reduced interest rate, tax exemptions, energy bonuses for private individuals, grant schemes, guidance and financing, and subsidized mortgage interest rates for high energy performing houses. The Energy Performance of Buildings Directive (EPBD) was revised in June 2018 to create more specific guidelines for a highly energy efficient and decarbonized building stock by 2050. The report notes that long-term renovation strategies are required in the EU.

In the US, the Department of Energy issued a document to establish a national definition of ZEBs. The US Congress also passed the Energy Independence and Security Act requiring that by 2030 all federal government building designs be fossil-fuel free. Canada is adopting federal building change and strict model building codes for 2020.

In the Asia and Pacific Region, Japan has committed up to ¥4 billion for ZEB financial subsidies. The Republic of Korea set a national goal for greenhouse gas reduction from buildings, and Australia developed the voluntary “National Carbon Offset Standards for Buildings” focused on managing emissions. Led by China, the members of the Asia-Pacific Economic Cooperation (APEC) produced a joint project report on nearly ZEB buildings which lays out current obstacles and barriers to ZEB market penetration.

The report also discuses large-scale ZEB initiatives from leading non-governmental organizations (NGOs) to promote ZEBs including by the World Green Building Council (WorldGBC), Architecture 2030, International Living Future Institute (ILFI), C40 Cities Climate Leadership Group, New Buildings Institute (NBI), and Net Zero Energy Coalition (NZEC).

Lessons Learned in Policy Implementation

Noting that the relative novelty of ZEB policies limits the analysis of lessons learned, the report outlines, among others, the following lessons:

• Achieving ZEBs that exclude plug loads is easier, especially in climate zones where heating and cooling loads are relatively moderate.
• Generating enough energy on site is challenging for buildings higher than four to six floors even if they are high performing and very efficient low energy buildings.
• The most successful jurisdictions use a mix of ambitious regional or national/state/provincial policy leadership in combination with grassroots local policy activity, environmental advocates, and industry leaders.
• Key risks relate to building operation resulting in higher energy consumption, excessive energy generation causing scaling back in other renewable energies, and “performance gaps” resulting from extra costs for ZEB achieving status.
• The need gather data to track progress and demonstrate the concept and feasibility can be a barrier to ZEB adoption.

Areas for further research

The final section outlines areas for further research, including the need for more studies on ZEB targets for tall buildings in dense urban settings, and proving the ZEB concept effectively to industry associations, governments and the public. [IPEEC Press Release] [Publication: Zero Energy Building Definitions and Policy Activity]