The emissions intensity of energy demand in the building sector has been increasing over the last decade.
The energy mix for the building sector is mainly based on electricity contributing a 68% share in 2019. A 1.5°C compatible pathway would lead to a level of electrification of around 82-84% by 2030, and up to 95% in 2050. The high share of renewable energy planned for the power generation (90% by 2025, 100% by 2035) would ensure the building sector is largely decarbonised. New Zealand would therefore likely see a pathway of declining emissions in this sector from current levels.
Increasing these renewable targets to a 1.5°C compatible 100% by 2030, along with increasing the use of hydrogen, could further decarbonise the sector. Our analysis shows that hydrogen could represent 4% of the building energy mix in 2030, and 16% by 2050. However, full electrification of buildings (heating, cooling, cooking) would remove the need to replace gas with hydrogen.
New Zealand has a Carbon Neutral Government Programme with a target for a carbon neutral public sector by 2025 where agencies will have to offset emissions they do not cut. New non-residential public sector buildings (valued over NZD 25m) will require a minimum 5-star green rating by 2022. The GreenStar rating entails an assessment across 10 different categories from direct impacts such as water use or materials to indoor air quality, emissions and energy use for example. The State Sector Decarbonisation Fund aims to replace public sector coal boilers although the government has not specified with which technology. The Building for Climate Change Program aims to set requirements for carbon emissions in building construction and decommissioning, and set a framework for operational (energy and water) efficiency.
Policy options for New Zealand include setting targets for non-public buildings; supporting energy efficient appliances; building renovations for energy efficiency; electrification of heating, cooling, cooking; and rooftop solar and battery storage.