There
is a lack of understanding on the different types of dynamics
of building stocks, in real life and in models. Moreover, there is
now a particular interest in the embodied impacts of construction
materials, since with the increasing efficiency of buildings operation,
embodied impacts gain more importance in the overall building life
cycle. This critical review wants to advance the understanding of
the type of dynamics, methods, and tools used. The well-known IPAT
equation is adapted for building stocks and three dynamics are defined:
spatial, evolutionary temporal, and spatial-cohort dynamic. A framework
is defined that can help researchers choose a method, tool, and dynamics
of input parameters depending on their research goal, case study,
and data. Moreover, generally valid conclusions are drawn, including
MFA is useful to model spatially dynamic material flows; GIS is needed
to include spatial dynamics. Retrofit, compared to construction and
demolition, is understudied and usually analyzed through top-down
methods. Material intensity and emission intensity are rarely modeled
in a dynamic way. Overall, scholars seem to perform increasingly data
intensive and complex studies tailored to a specific case study. However,
there are big differences in the quality depending on the dynamic
of input parameters.
Africa is currently experiencing rapid population growth and accelerated urbanization. This demographic shift will require a large amount of new construction material resulting in substantial environmental impact. For many cities on the continent, data gaps make specific quantification and robust prediction of this impact highly difficult. This article presents a method to assess the stock dynamics and embodied emissions of a rapidly growing urban built environment using a bottom-up, typological approach. This approach allows for the identification of appropriate engineering solutions for decarbonization by localizing embodied greenhouse gas (GHG) emissions in the different constructive elements with a revisited Sankey diagram. Different alternatives regarding housing type and construction techniques are compared. The city of Johannesburg is used as a case study to illustrate the relation between building types, technologies, and embodied GHG of its residential building stock. This new visualization uncovers the most material-and GHG-intense dwelling types and building elements. The adapted Sankey represents the building stock and its drivers in a simple way, allowing clear understanding of the consequences of potential alternatives. The business-as-usual scenario indicates 100.5 megatons carbon dioxide equivalent (Mt CO 2eq) for new construction between 2011 and 2040. The results of the dynamic model over time show that only a combination of a densified building stock with multistory buildings and the use of alternative construction materials and techniques show real potential to decelerate GHG emissions (33.0 Mt CO 2 -eq until 2040) while aiming to provide adequate and sustainable housing for all.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.