Development of a building adaptability indicator to encourage designing adaptable high-rise buildings

Abstract

Policy makers have set the goal to reach a completelycircular economy by the year 2050 in the Netherlands. This means that theconstruction industry should shift from its current ‘take-make-waste’ approachtowards a circular approach. The number of buildings of more than 100 m inheight are increasing in the Netherlands, due to the lack of horizontal space.This means that strategies should be investigated on how high-rise buildingscan be constructed in a circular manner. It is found that there are currently alarge number of high-rise buildings that are being demolished. The main reasonfor these demolition cases is that building owners want to replace theirbuilding with a new one, with new technologies and perhaps a new buildingfunction. Abuilding that is adaptable to these changes would not have to bedemolished,  which is why the circularitystrategy of Design for Adaptability is interesting for high-rise buildings.There is a lack of research on the measurement of theDesign for Adaptabilitystrategy on the building level. Therefore, in this research a BuildingAdaptability Indicator is created to measure the adaptability of a building. TheBuilding Adaptability Indicator is constructed from a study on how adaptabilitycan be achieved in a building. It is found that building adaptability isgoverned by three sub-indicators: openness, reserved capacity, andfloor-to-floor height. The Building Adaptability Indicator helps structuraldesigners to prove what amount of adaptability can be achieved with a certainextra material use. It is found that the adaptability can be increased with126% by increasing the structural element dimensions by up to 60%, leading to atotal material volume increase of 38%. Additionally, it is found that purelyfrom amicro economics point of view, the investment into a high adaptabilitycannot be justified due to the high initial investment combined with a low rentincome. However, from a macroeconomics point of view, policy makers caninfluence the construction industry to invest in buildings with a lowenvironmental impact, which is already done by the Dutch government throughsubsidies. Currently, adaptability is not considered in the calculation of theenvironmental impact, which means that investors do not have an incentive toimplement adaptability in their buildings. In this research, the BuildingAdaptability Indicator I simplemented in the calculation of the environmentalimpact, which leads to the conclusion that buildings with a high adaptabilityare more interesting from a circularity point of view. It is concluded that atthe moment, only investors with circularity ambitions will invest in adaptablebuildings. Investors that lack circularity ambitions can be encouraged toinvest in adaptable buildings as well. This can be done by implementingadaptability in the calculation of the environmental impact, for which ownersof adaptable buildings will receive subsidies. This will shift the constructionindustry more towards adaptable buildings, which will prevent demolition andlead to a lower environmental impact across the industry.