The Massachusetts Institute of Technology gets their hands dirty as they investigate which buildings produce the most carbon emissions.
Buildings are by far the greatest contributors to global greenhouse gases. They account for a mammoth 39% of CO₂ emissions in the U.S. It is for this reason that MIT’s Concrete Sustainability Hub undertook a study of both residential and commercial buildings to garner a greater understanding of how these buildings function, with a view to finding ways to build greener in the future.
The study differs from others of its kind as it takes into consideration the entire life cycle of the building from construction, through operation and on to disposal. This means that all materials used to construct the building must account for their energy usage from extraction, to processing, transportation and finally to construction. This is an important point for the ICF or insulated concrete form construction which has often been criticized for the high energy output required to produce concrete. ICFs are a Polystyrene casing filled with concrete which create walls that use thermal mass to insulate homes. Critics have argued that the creation of concrete takes more energy than the timber used for conventional buildings. The study also calculated operating costs for both types of homes and the cost of disposing of the home after a 75 year period.
The year-long study has looked at single and multiple family homes constructed using traditional wood frame methods and insulated concrete forms. The study scrutinized homes in both hot and cold climates.
The findings revealed a significant saving on energy and ventilation costs for homes constructed using ICF technology. Although the concrete used in the ICF construction used more energy to produce than a wood frame home, the 20% or more saving on energy recovered initial carbon emissions within a few years. One must also be cognisant of the fact that about 90% of the CO₂ emissions were due to use rather than construction and disposal emissions.
Wood frame construction
This initial report was released in December and shows the overwhelming improvement ICF construction offers in energy consumption. The study is ongoing as MIT investigates other climates and technologies in passive or net zero homes (homes that use very little energy). These homes combine the insulation offered by ICFs with renewable energy to create zero energy homes that are self-sufficient. Co-director of the project, John Ochsendorf was excited about the findings and said he hopes “… to create a roadmap for better infrastructure in the future.”