Theoretical Analysis and Comparison of the Thermal Performance, Construction Costs, and Maintenance Complexity between a Conventional and an Intensive Green Roof

Abstract

In this paper, a comparison between a conventional flat roof and an intensive green roof was made. Emphasis was on thermal conductivity of individual layers, the calculation of thermal resistance, and calculation of the thermal transmittance coefficient through both roof variants. The calculations for the two analysed roof variants were made for a building located in the town of Rijeka on the Adriatic coast. This paper also presents the construction technology comparison of the analysed roof variants. The construction cost was also analysed for both roof variants together with time needed for the execution of variant solutions. Finally, maintenance plans for both roof variants were presented in this paper. The results show that the construction costs of an intensive green roof are higher than the construction costs of a conventional flat roof and that the maintenance of the intensive green roof is more complex. On the other hand, the results of the analysis also show that constructing a green roof will result in more energy savings in the long term than in the case of constructing a conventional flat roof. In addition, there are several other benefits that go in favour of constructing an intensive green roof. Most prominent among those benefits are environmental and social benefits.

Enhancing Urban Sustainability through Green Roofs: A Thermal Performance Evaluation in Dubai

“…According to Zaid et al, there are several guidelines for green roof maintenance including the US Environmental Protection Agency (EPA) Design Guidelines and Maintenance Manual for Green Roofs, which is the most comprehensive, focusing on various maintenance elements except for monitoring performance (Zaid et al, 2022). According to Juricic et al, a green roof maintenance plan should include visual checks of the waterproofing layer, thermal insulation layer, heat fluxes, temperature values, load-bearing structure, and other maintenance elements (Juricic et al, 2021). Further, visual inspections include checking vegetation health and state of cleanliness, pest control, removal of infested or dried vegetation, debris collection, fertilization, pruning, reaping, seeding or replanting, scheduling actions after floods or storms, and watering (Juricic et al, 2021).…”

“…According to Juricic et al, a green roof maintenance plan should include visual checks of the waterproofing layer, thermal insulation layer, heat fluxes, temperature values, load-bearing structure, and other maintenance elements (Juricic et al, 2021). Further, visual inspections include checking vegetation health and state of cleanliness, pest control, removal of infested or dried vegetation, debris collection, fertilization, pruning, reaping, seeding or replanting, scheduling actions after floods or storms, and watering (Juricic et al, 2021). Watering helps to induce the cooling and humidifying effect of green roofs, regardless of vegetation species (Zhang et al, 2020).…”

“…Watering helps to induce the cooling and humidifying effect of green roofs, regardless of vegetation species (Zhang et al, 2020). Maintenance costs for intensive green roofs are generally higher than for extensive green roofs and conventional flat roofs (Zaid et al, 2022;Juricic et al, 2021).…”