Building codes for energy efficiency and renewables
As the world transitions to a low-carbon economy, the construction industry plays a critical role in reducing greenhouse gas emissions. The building sector accounts for approximately 40% of global energy consumption and one-third of global greenhouse gas emissions. Building codes are essential tools for governments to promote energy efficiency and the use of renewable energy sources in buildings.
Building codes can be mandatory or voluntary, and their degree of stringency varies considerably across cities and countries. In some countries, building codes apply only to municipally owned structures, while in others, they also apply to privately owned buildings. Building codes can apply to new buildings only or also to existing structures.
Building codes may entail energy use/efficiency targets for new buildings, specify insulation standards, and decree building design choices to increase building energy efficiency and therefore lower the amount of heating and cooling energy required. Some building codes prescribe measures that ensure new buildings are “solar ready” or mandate the use of solar water heaters or solar PV panels for new construction.
At the end of 2019, around 41 countries had implemented national building codes to promote energy efficiency and renewables in buildings. Some cities have played a pioneering role for years, adopting ambitious targets, policies, and fiscal and financial incentives to improve energy efficiency, reduce the greenhouse gas footprint of buildings, and enhance the role of renewables.
In the United States, several states have adopted building codes that promote the use of renewable energy sources in buildings. For example, California’s building codes require all new residential buildings to have solar panels installed on the roof. The state aims to achieve net-zero energy use in all new residential buildings by 2020 and in all new commercial buildings by 2030.
In Europe, the European Union’s Energy Performance of Buildings Directive requires member states to establish minimum energy performance standards for new and existing buildings. The directive also mandates that member states develop long-term strategies to decarbonize their building stock.
Building codes can be an effective way for governments to promote the use of renewable energy sources in buildings. By setting energy efficiency standards and promoting the use of renewable energy sources, building codes can help reduce greenhouse gas emissions from buildings and accelerate the transition to a low-carbon economy.