Decarbonization of the building sector : A systematic map of the roadmaps, strategies and action plans for Net-zero and Net-positive energy buildings around the world

Sammanfattning: Buildings account for 36% of global final energy consumption and almost 40% of total direct and indirect CO2 emissions (IEA, 2019). Net Zero Energy Buildings (NZEB) are an option to reduce both energy consumption and environmental emissions from the building sector. This systematic map examined what evidence exists worldwide about efforts to implement NZEB from governments and institutions in the form of action plans with clear goals and targets, called roadmaps. The primary research question was: ‘what is the extent and distribution of evidence on Roadmaps for NZEB and their targets around the globe?’. Both academic and grey literature were searched for in English. Using specified search terms, the SCOPUS database was searched along with 13 institutional websites. Searches were conducted to include studies published after 2010. This process was repeated twice – first as a pre-study to inform the search string and augment the study design, and second to proceed through to data extraction. Screening was conducted at two levels: Title and Abstract Level and Full-text level. Metadata was extracted from relevant studies at Title and Abstract level, including location of study and type of study. The pre-defined inclusion criteria were Population (P=Buildings), Intervention (I=Roadmap), and Outcome (O=NZEB) at both levels. The information extracted from the included studies were names of roadmaps, roadmap targets or ambitions, country of origin of roadmaps, year of issue and level of institution. Reference lists were searched in order to include more roadmaps. Trends in the evidence are reported in a narrative synthesis. Of the 2749 studies returned through two searches, 20 unique studies were included at the data extraction level. Since study design was inconsistent throughout, metadata was extracted from 274 studies at Title and Abstract level during the second search and screening process. Most studies were reported from Europe and North America and the focus of these studies was mostly recommendations to policy makers. In addition, the data extracted from 20 studies, the grey literature and reference lists led to a finding of 127 Roadmaps, Policies or Plans from 27 countries. This systematic map provided a database useful for researchers to conduct a full systematic review in the future. The need for policy makers to set-up concrete implementation strategies was emphasized and a gap in implementation efforts was observed barring a few regions of the world.