Abstract:
Although cities significantly contribute to global carbon emissions, they also have significant
potential to function as carbon sinks through building-integrated vegetative infrastructures
(BVIs), such as green roofs, green walls and vertical terraces. These represent climate-smart
engineering solutions that can enhance carbon sequestration (CS), though research on their
effectiveness remains limited. The study aimed to (1) evaluate the CS potential of various BVI
types, including green roofs, green walls and vertical terrace and (2) understand stakeholder
perceptions and the factors influencing BVIs. Three buildings integrated with BVIs and located in
urban environments were purposively selected for field data collection, including plant height,
canopy area, base height and diameter, that were required for quantifying CS. Calculations were
conducted individually for different selected types of structures per area and per time. The i-Tree
Eco tool was used to quantify CS, carbon storage, and pollution removal. Semi-structured
interviews were conducted with 40 professionals, including architects, civil engineers, quantity
surveyors and sustainability officers those most responsible building construction to assess their
awareness, experience and perceptions regarding BVI implementation using five-point Likert
scale. Results indicated that vertical terraces exhibited the highest CS rates (1.326–3.81
kg/m²/year), followed by green walls (0.749–4.62 kg/m²/year) and green roofs (1.889
kg/m²/year). While awareness of BVI for CS was relatively high, practical experience remained
limited (Wilcoxon signed-rank test, Friedman test). The hotels and office sectors emerged as the
most suitable for BVI adoption, whereas the educational and manufacturing sectors faced
structural and financial constraints (Wilcoxon signed-rank test). Experts expressed the
importance of long-term evaluation methods, such as benefit-cost ratio and net present value, to
justify sustainable investments over short-term gains (frequency-analysis). This study highlights
the urgent need for scale up nature-based solutions that strengthen urban sustainability and
support climate-smart design and policy against climate change.
