Back to Basics: Improve Building Performance Using Vegetation

Atmospheric CO 2 concentrations have reached 416 ppm, surpassing the highest known concentration in the last 400,000 years by over 38%. The United States is the second largest CO 2 emitter in the world, with residential electricity use accounting for 20% of the total emissions. Therefore, a radical reduction in greenhouse gas emissions from the housing sector is necessary to mitigate the consequential effects of global warming. Studies on housing retrofits focus on improving the energy efficiency of buildings, but do not address the potential for bio- sequestration. In this report, vegetation-based retrofit strategies were studied for their potential impacts on building energy efficiency, as well as, their potential to sequester carbon. A base model for a single-family home was constructed using DesignBuilder software. Climate data from Phoenix, AZ was applied to simulate energy performance and equivalent CO 2 emissions for ten retrofit scenarios. During each simulation, only one material was altered in order to understand the impact of individual materials. Clay and earthen materials were added to the exterior walls and roof to mimic that of a vertical garden and green roof, shading was included to mimic the impacts of climbing vegetation. Results showed that soil based vertical gardens and green roofs save between 1,200 and 3,000 kWh per year, while the associated equivalent carbon emissions increased up to 1,400 kg CO 2 . Shading did not significantly impact energy efficiency or equivalent carbon emissions. The simulation, however, did not account for the cooling effects of evapotranspiration that may be associated with plants. Based on literature review, retrofitting with algae photobioreactor facades shows promising potential for bio-sequestration while also providing an insulative barrier for the buildings. By furthering research on living building systems, it is possible for buildings to become energy producers rather than environmental energy consumers.

Monday Poster Session
Jordan Porter
Related Conference Themes
Built Environment