Building a circular economy

Sammanfattning: The construction sector is one of the biggest contributors to global CO2 emissions and buildings account for a significant part of the energy use in Sweden. Population growth in combination with economic development is putting more pressure on the environment, resulting in escalating consumption trends and larger quantities of raw material extraction. Policies and directives are promoting a circular economy in material flows. Waste avoidance and reuse are priorities in the EU waste hierarchy. Environmental issues are apparent to be a subject of urgency and will conceivably remain problematic for future generations. Drivers and barriers for implementing a circular model in the Swedish construction industry was studied with interviews, questionnaires and calculations. A fictive house was used as reference point in calculations and survey. In total, 19 interviews and questionnaires were performed. Indicating quality consistency, quality assurance, logistics, timeframes and availability to be the major barriers. Furthermore, the need for a coordinating actor in the reuse process is a reoccurring subject. An additional survey was distributed to all 290 municipalities in Sweden to investigate the flexibility in regulations addressing the poor energy performance in reused windows. The survey results show that using windows with U-values of 2.0 W/(m^2 ∙ K) is accepted if figures for ”installed effect”, ”average U-value” and ”EPpet" is within the limits regulated in the building codes. Calculations on LCA and LCC was performed with the purpose of investigating the inbound energy in comparison to energy savings by installing a new ”low energy” window. Results indicate that even windows with bad energy performance are environmentally profitable in many cases when compared to the inbound energy of manufacturing a new high performing window. LCC results indicate that if the windows are to be reused and estimated to last 25 years, the cost involving restauration, transport, dismantling and installation is financially feasible up to around 70 000 SEK - 100 000 SEK depending on inflation and growth rates. Concluding from interviews, the feasibility of incorporating circularity to the building sector in Sweden is highly dependent on timeframes. It is apparent that the reuse option must be presented at the earliest of stages, placing focus on contractors and architects. Also, building with the intent of dismantling is seen as a fundamental part of the circular model. Possible drivers are seen as a combination of government tax reductions on reused components and raised taxes on unsorted waste.