The evaluation of sufficiency strategies in the building sector using life cycle assessment

Abstract

The building sector has a monumental impact on the planet’s environmental state. Despite ongoing efforts, emissions are growing, partly due to increasing consumption, where resource improvements are consumed by expenditure. Efficiency and renewables through technology and sustainable resources cannot reduce the impact of growing demand without a decrease in overall consumption. In recent years, sufficiency has been highlighted as a mitigation strategy with great potential to reduce the environmental impact of the built environment. However, there are few clear examples of definite strategies in the building sector. Furthermore, many building sustainability frameworks include a life cycle assessment, but the result is typically presented as total impact per m2. This makes sufficiency problematic to evaluate, as the main strategies for the building sector are to reduce impact by reducing building and unit size, material demand, and energy consumption. There are currently few examples of sufficiency in LCA, and none are related to the building sector. For sufficiency to be successful in the building sector, the effect of the strategies needs to be quantifiable by LCA, as this is a prevalent method within sustainability and building performance analysis. This thesis explores how LCA can be applied to estimate the effect of sufficiency strategies within housing. The study implements the idea of Sufficiency LCA, using a sufficiency functional unit along with the conventional functional unit, evaluating possible measurements and the effect of strategies. Furthermore, the influence of functional units is studied by testing various units that could change the perception of the building’s impact and provide a more holistic assessment. The thesis concludes that a comparison to show the impact saved is required to evaluate sufficiency. One option is through an additional functional unit measuring the savings effect (a sufficiency functional unit), which is most effective for sufficiency strategies regarding unit sizes and functions. The second option is comparative analysis with other products, which works better for strategies concerning material use. Furthermore, including area per capita or capita as a functional unit would better present the function and size of a building, along with highlighting crucial sufficiency strategies, such as density and co-living. Moreover, multiple trade-offs can be seen between embodied and operational emissions and between production, maintenance, and end-of-life stages for materials.