A new study has revealed that global innovation in the building sector with the potential to help fight climate change already exists.
The new collaboration between construction experts and leading international academics, including senior members of the Intergovernmental Panel on Climate Change, revealed that it is possible to achieve net- or nearly-zero energy building outcomes in nearly every part of the world – including both developed and developing countries – at costs in the range of those of traditional projects.
According to the study, technologies and skills already exists at costs that are in the range of conventional buildings. The building sector contributes approximately 36% to final energy demand and 39% to process-related greenhouse gas emissions. Therefore maximising energy efficiency for all building energy uses is found as central to net- zero targets and the transformation of the building sector toward net-zero energy and low embodied carbon buildings is a key component of meeting climate neutrality targets.
The study found that the cost of sustainable buildings can match or even be less than those constructed through traditional methods, because project spend related to energy efficiency is low. For example, the City of Vancouver anticipated a modest increase in construction costs as a result of increased building code performance requirements but instead experienced a cost decrease of 1%.
“Buildings are often the largest consumer of energy and source of emission in cities, and frequently represent the lowest cost option for reducing emissions,” says David Miller, Director, International Diplomacy at C40 Cities Climate Leadership Group and former Mayor of Toronto.
“The findings in this important paper highlight the experience of leading cities in which committed leadership has overcome the challenges to enable better, more comfortable, healthy, affordable and sustainable homes and buildings for all.”
Despite the fact that the study highlights the ease with which many cities have begun the transition to sustainable housing, challenges still remain. The greatest technological difficulties are seen in high-rise commercial buildings in hot and humid climates and in retrofitted historic heritage buildings. Deep retrofits are also costly in the short term, and although they may cost less over time, innovative financing is often required upfront.
“The sustainable cooling of buildings is a major challenge,” says Radhika Khosla, study co-author and Senior Researcher at the Smith School of Enterprise and the Environment, University of Oxford.
“In a warming climate, building energy use will go up even if cooling is as efficient as possible. Rising affluence, space and comfort needs are set to dramatically increase energy demand – with corresponding increases in greenhouse gas emissions. However, there are solutions: for example, shading and wind-channelling designs to block the sun and allow for natural ventilation in high-rises.”
However, recognising their environmental, climate, social, health, productivity, economic, and other advantages, many jurisdictions have successfully introduced policies and incentives to overcome these barriers and thus increase their market penetrations. China alone has built more than 7 million square meters of Passive Houses with significantly more under construction; New York City, Vancouver, Brussels, Tyrol, and other jurisdictions have introduced innovative policies and incentives to catalyze market transformation toward Passive House standard buildings.
“Having buildings that achieve nearly zero energy is absolutely possible in the hot-humid climates of Asia, as more and more exemplary cases and key techniques are found,” says Yvonne Chan, study co-author and Senior Programme Coordinator, Delta Electronics Foundation.
According to the new research, the key to achieving net zero targets is the maximization of energy efficiency through building features, with remaining energy requirements generated from locally produced, renewable energy sources such as solar panels. The use of renewable materials, such as timber, can also help decrease CO2 emissions. Bio-based materials could represent a double win in construction: first, by replacing energy- and carbon-intensive materials such as cement, and second, by storing carbon temporarily.
Overall, the study highlights that the global outlook on sustainable housing is positive. Strategies to minimize embodied energy and carbon in building materials are gaining significant attention and include material efficiency, recycled and reused materials, durable components, design and new materials, replacing carbon-intensive materials by bio-based ones, as well as carbon capture and utilization.
Leading jurisdictions have also taken action to transform their building stocks and introduce specific exemplary policies and programs, overcoming perceived and real barriers in the process.