Green Roof Materials Research Articles

Eco-Innovative Construction: Integrating Green Roofs Design within the BIM Framework

This research delves into the integration of green roofs elements and parameters with Building Information Modeling (BIM), a pivotal advancement in sustainable urban construction. Aligning with the United Nations Sustainable Development Goals, particularly Goal 11, this study explores how this integration can address global challenges like climate change and resource depletion. Using the Dynamo Visual Programming Language within Autodesk Revit, this research develops a computational modeling approach for green roofs, focusing on their thermal and structural characteristics under varied environmental conditions. Key findings demonstrate the significant influence of substrate and drainage material combinations on green roofs’ thermal performance, highlighting the need for tailored designs based on climatic conditions. This study also emphasizes the importance of considering structural performance in both dry and saturated conditions for overall building integrity. This research identifies gaps in current practices, such as limited focus on specific green roof materials and reliance on certain software tools, suggesting the need for broader material selection and software adaptability. Future research directions include expanding material selections, exploring diverse environmental conditions, and integrating green roofs elements and parameters with various BIM software platforms. This study’s implications extend to stakeholders in the construction industry, offering a framework for architects, urban planners, and policymakers to design and implement green roofs aligned with environmental goals. This work contributes to the field by proposing a novel approach to sustainable construction, integrating ecological design with digital technology, and setting a new benchmark in the integration of green roofs design with BIM. By addressing these aspects, this research paves the way for future developments in sustainable urban construction, enhancing the efficiency, sustainability, and resilience of urban communities in line with global sustainability objectives.

Eco-friendly green roof solutions: Investigating volcanic ash as a viable alternative to traditional substrates

This research investigates the potential of volcanic ash as a green roof material, focusing on its thermal conductivity, physical characteristics, and permeability. Laboratory tests were conducted to determine thermal conductivity under different moisture conditions using two measurement devices, TLS 100 and HFM 436/3/1 Lambda. The results revealed that thermal conductivity increases with higher moisture content, indicating improved heat conduction as the material becomes more saturated with water. Particle size distribution analysis demonstrated that the majority of volcanic ash particles fall within the range of sand and gravel, providing a porous and well-draining material. Sand-sized particles create interconnected voids, facilitating efficient water movement, while gravel-sized particles enhance structural stability and load-bearing capacity. The limited presence of silt-sized particles further validated the material's suitability for green roof applications. Permeability tests on loosely compacted volcanic ash revealed higher permeability at 0% compaction, aligning with intended green roof configurations. This high permeability ensures effective drainage, preventing water accumulation and promoting healthy vegetation growth. At 20% compaction, the material still effectively managed water under potential compaction forces, striking a balance between drainage and water retention. Visual examination of green roof samples demonstrated that volcanic ash substrates resisted weed growth due to the absence of fertilization. While the commercial substrate exhibited better vegetation development due to added nutrients, volcanic ash substrates supported vegetation survival throughout the summer period with an irrigation system, reducing maintenance and lifecycle costs. In conclusion, the research findings indicate that volcanic ash possesses desirable thermal properties, a suitable particle size distribution, and favorable permeability characteristics for green roof applications. Its potential as a sustainable and cost-effective alternative to commercial substrates is evident, offering resilient urban landscapes with reduced environmental impact. Further exploration and optimization could solidify volcanic ash as a valuable component in advancing green roof technologies, promoting sustainable urban development.

Thermal properties of green, white and other building roof materials and solar insolation: A case study in New York City

This report presents results from a case study of surface temperatures of an urban green roof, a white roof, and other roof surfaces, at Hunter College, of the City University of New York. The analysis includes manual as well as automated observations between 2012 and 2016. The cooling effect, defined as the surface temperature differences between the green and white surfaces compared to a black surface, are often greater than 20 °C, and sometimes greater than 30 °C for both green and white roofs. Solar insolation is found to be the best predictor of the cooling effect, explaining over 72% and 77% of the variance for green and white roofs (respectively), with a 2-3 °C enhanced cooling effect for every 100 W/m2 increase in solar insolation. The response times of both green and white roofs to solar insolation is estimated to be 20 min (±10 min). Green roofs are found to have a slight cooling advantage (∼1.7 °C) over white roofs at higher solar insolation (∼1000 W/m2) and higher surface temperatures (∼45 °C). Key components of the surface energy balance are considered to help explain the observed thermal behavior of the green and white roofs. Manual observations, instrument maintenance, as well as data transcription and quality control, were performed largely by undergraduate students, demonstrating that green infrastructure can provide valuable learning experiences that may be difficult to otherwise provide in urban environments.

Evaluation of energy efficient building envelope alternatives for sustainable cities

This study is aimed to create an exemplary project to present the contribution of the new buildings to energy savings when the residential buildings are transformed into green buildings. To create a sustainable built environment in residences, this study emphasizes that low-energy building strategies be combined with efficient and high-performance natural-sourced materials. Our findings show that using a natural-sourced material as the building envelope material has an impact on the use of primary energy and energy costs of the alternatives studied. In this study; In the case of replacing the building external wall components of an existing construction designed with internal insulation in the climatic conditions of Ankara, the change in energy performance has been investigated. The analysis was done with the help of BIM-based Revit Program and “Green buildings studio” where energy simulations were created. In the study, 54 different wall combinations were created by modeling combinations of different construction (porous, gas concrete, and pumice bricks), insulation (glass wool, rock wool, sheep wool, PUR, XPS, and EPS) and, roof (tile, asphalt shingle, and green roof) materials. When the outputs obtained from the analyzes were evaluated, the lowest energy consumption values were observed in the combination of pumice brick wall, green roof, and polyurethane insulation materials. In this scenario, the annual fuel consumption per square meter is determined as 30000.6 MJ/m2. On the other hand, the highest energy consumption values were observed in the combination of porous brick wall, tile roof and sheep wool insulation materials. In this scenario, the annual energy consumption per square meter is determined as 30026.6 MJ/m2. Although there are not high numerical differences between the findings, it has been observed that the results give consistent results with the thermal conductivity coefficients of the materials used in the combinations.

Sensitivity analysis and weather condition effects on hygrothermal performance of green roof models characterized by recycled and artificial materials’ properties

This study conducted a sensitivity analysis and assessed the effects of long-term weather conditions on green roof models, including recycled and artificial materials. Climate conditions can affect the hygrothermal performance of green roof materials, but this important issue has hardly been evaluated for drainage and substrate layers made of recycled and artificial materials. Climate change makes it unclear how well green roofs will perform hygrothermally. Moreover, the heat flux sensitivity to the thickness and physical characteristics of green roofs with artificial and recycled materials has received less attention. This study applied three weather scenarios on green roof models with artificial and recycled materials: the beginning, middle, and end of the 21st century. As per the results, at the beginning and middle of the 21st century, substrate layers' water content was roughly nine times more than the drainage layers'. At the end of the 21st century, the comparable difference was 6.5 times larger. During the summer and the beginning of autumn, the green roofs’ thermal performance with recycled and artificial materials was improved until the end of the 21st century. The entire parameter change demonstrated the scatter of thermal conductivity, density, and thickness effectively influenced the dispersion of heat flux for the green roof layers. Also, the scatter of density was more effective in heat flux dispersion for substrate layer than drainage layer.

The potential of coconut waste as green roof materials to improve stormwater runoff

Urbanization is one of the leading causes of urban flooding as rapid development produces more impervious areas in cities. The application of green roofs is regarded as an effective technology to minimize the adverse effects of urban development. The stormwater management capacities of green roofs have been extensively acknowledged, and they can retain rainfall and detain runoff. Nevertheless, Malaysia has experienced few green roof applications, and only limited literature is available concerning such topics. Additionally, the incorporation of waste and recycled material in green roof designs must be considered to ensure such projects benefit the environment as well as the economy. Therefore, the construction of a green roof utilizing recycled waste materials was attempted. An extensive green roof was constructed using beach morning glory and creeping ox-eye plants as vegetation layers, along with coconut waste, i.e., coconut fiber and coconut shell, as the medium for the filter and drainage layer, respectively. According to the results, the use of recycled coconut waste materials in the green roof operations reduced the peak flow by as much as 86%, while the use of commercial materials led to a reduction of 67%.

Water permeability, water retention capacity, and thermal resistance of green roof layers made with recycled and artificial aggregates

Substituting natural aggregates in the green roof substrate and drainage layers with lightweight artificial and recycled coarse materials is an eco-friendly alternative for applying lower load to the rooftops and preserving natural resources. However, a lack of precise understanding of the thermal resistance, water passing ability, and water holding capacity of green roof materials, including recycled and artificial materials, has raised a demand for measuring their Rc-value, water permeability, and water retention capacity as three main indicators for green roof systems. This study comparatively evaluated the thermal resistance, water permeability, and water retention capacity of green roofs with substrate and drainage layers, including coarse recycled and artificial materials. Different kinds of coarse granular aggregates were separately used for the drainage layer, including Natural Coarse Aggregate (NCA), Recycled Coarse Aggregate (RCA), Incinerated Municipal Solid Waste Aggregate (IMSWA), and Lightweight Expanded Clay Aggregate (LECA). The substrate layers were made with coarse recycled materials (SC) and without coarse recycled materials (SP) in wet and dry states. The outcomes revealed the highest thermal resistance and the lowest weight were obtained for 20-cm green roofs with a 15-cm substrate layer and 5-cm drainage layer of LECA. The water permeability of NCA was obtained 1.5 times more than that of LECA, whereas there was no significant difference between the result of the former, RCA, and IMSWA. The water retention capacity of the LECA was two times higher than that of the NCA. SC and SP satisfied the water passing and retention criteria given for green roofs.

Rethinking green roofs- natural and recycled materials improve their carbon footprint

Green roofs contribute to climate regulation and urban heat island mitigation, thereby counteracting heat stress. Ecosystem services of green roofs are discussed, but their production and demolition processes have not been fully addressed.In this study, a life cycle analysis (LCA) was conducted to assess the possibility of creating of a carbon-neutral green roof and to evaluate and compare the global warming potential (GWP) of two green roofs: 1) a conventional green roof (GR-c) with expanded clay, pumice, and compost in the substrate and a polypropylene drainage, and 2) an alternative green roof (GR-a) with recycled bricks and compost in the substrate and a cork drainage. LCA refers to a functional unit (FU) of a 218 m2 green roof (substrate depth of 9 cm; lifespan of 40 years). The results showed that the use of a brick substrate can reduce the GWP to 3139 kg of CO2 eq/FU (−50%) and the use of cork drainage to 441 kg of CO2 eq/FU (−69%). Apart from production, demolition was a key element required for further improvement, accounting for 32% (GR-c) and 55% (GR-a) of the GWP. Once produced, a green roof can take up 783 gCO2/(m2·a) because of plant uptake. To become CO2-neutral, a GR-c and GR-a would have to last 88 and 53 years, respectively. Furthermore, the GWP was influenced by green roof maintenance and plant CO2 uptake.We concluded that recycled bricks and cork are promising green roof materials.

A COMPARISON OF HEAT PERFORMANCE BETWEEN GREEN ROOFS ON CONCRETE AND GREEN ROOFS ON CORRUGATED ZINC

Green roofs are generally applied to concrete roofed buildings. This study compares the thermal performance of green roofs that occur in corrugated concrete and zinc to expand green roof innovation. The study experimented on a method using the 2011 Ecotect computer simulation. The results showed that the difference in temperature reduction in corrugated zinc was higher than in concrete. Changes in heat outside the roof space on both have a number that has a relatively small difference, but the difference in heat is visible in the inner space. Based on the thermal performance of the roof, the use of corrugated zinc roofs as the base of the green roof in the building could be an alternative green roof material besides concrete.

Novel application and reused materials for extensive green roof substrates and drainage layers in Japan – Plant growth and moisture uptake implementation –

This study investigates the potential utility of reused materials as an alternative material for commercial substrate and drainage layers. The performances of reused materials were assessed using turf with trays on a roof for two years in Chiba, Japan. Two types of materials, a commercial green roof substrate and cocopeat, were used as the substrate. For the drainage layers, five different materials were used: a commercial green roof drainage layer, bamboo stems and nodes, and polyethylene terephthalate (PET) bottle caps and bottoms. In addition, a sample without any drainage layer was used. The trays were prepared with the combination of these two substrates and six drainage applications. Overall, reused materials were observed to function well as commercial green roof materials. The turf in cocopeat was able to survive better than turf in commercial green roof substrate. In the drainage layers, some reused materials, such as the PET bottle caps and bamboo nodes, showed higher final plant coverage than commercial drainage layers in cocopeat. Our study has addressed the importance of realizing the original substrate and drainage layer using reused materials for developing sustainable and inexpensive green roofs.

The willingness and perception of people regarding green roofs installation.

Developing economies are facing multifaceted problems like dramatic increase in motorized traffic, urban heat island, urban sprawl, and climatic changes. Environmental Performance Index report states that Pakistan is on 169 among 180 countries due to ill-planned development on prime agriculture land, poor air, water quality, and jeopardizing ecosystem of the country. The change of land uses from the natural to the built environment has created problems like loss of vegetation and habitat, enlarged surface flow, and heavy floods. However, this study addresses this core issue by taking responses from the residents of Lahore, Pakistan. Current research focuses on the willingness and perception of residents regarding the adaptation of green roof technology. The resident perceptions are obtained by a structured questionnaire and analyzed by using statistical techniques. The findings of the research highlight that adaptation of green roof is primarily linked with the four factors, i.e., awareness of green roof among all stakeholders, special provision in building regulation concerning green roof, sustainable environmental consciousness, and subsidized cost of green roof materials.

Selection and control of green roof materials based on sponge city perspective

This article starts from clarifying the connotation relationship between sponge city construction and green roof, and analyzes the construction plan and the best material selection under the influence of sponge city construction. Then introduces and compares the construction of the green roof under the sponge city background and the materials that can be used at the structural level, the evaluation index system of material selection based on DEA, five kinds of materials of input/output ratio of SBS modified asphalt waterproof coiled material is 0.477, TPO thermoplastic polyolefin waterproofing material is 0.255, PVC waterproof coiled material is 0.335, EPDM waterproofing material is 0.292, and spraying polyurea waterproof coating is 0.245. Comparison and analysis to choose spraying polyurea waterproof coating as the green roof material is more reasonable. This will provide a basis for the design of green roof materials in the context of a sponge city.

Biochars and hydrochars prepared by pyrolysis and hydrothermal carbonisation of pig manure

Pyrolysis of organic wastes for biochar preparation has been proved as a useful way of waste management. However, the elevated water content of some organic wastes precludes its use without a drying step before pyrolysis treatment. For this reason, hydrothermal carbonization (HTC) of wet biomass could be an inexpensive alternative management method. The main objective of the present work is to compare the properties of biochars and hydrochars obtained from thermal treatment of pig manure. Biochars were prepared at 300 °C (BPM300), 450 °C (BPM450) and 600 °C (BPM600) and hydrochars were obtained using a pig manure solution (ratio 30:70) that was heated at 200 °C (HPM200), 220 °C (HPM220) and 240 °C (HPM240) during 2 h. Characterization of biochar and hydrochar samples showed that pyrolysis led to chars with more aromatic structures and high thermal stability while HTC process originated chars with more aliphatic structures. HPM220 and HPM240 showed the highest values of field capacity water content and available water probably due to their higher O/C ratios and the macroporosity development in the range from 200 to 30,000 nm. These results suggested that HTC could be an interesting method to obtain soil growing media or green roof materials with adequate hydrophysical properties.

Wpływ miąższości reaktywnej warstwy drenażowej na odpływ fosforanów z zielonego dachu

The green roof runoff may be contaminated with phosphorus. The source of P pollution can be a substrate layer. The research was carried out to determine an optimal ratio of P-reactive drainage layer (RM) to substrate layer (S) in a green roof construction. The main goal of conducted column experiment, was to examine P-removal efficiency of drainage layers in different thickness. The green roof material used in the experiment is a commercially available substrate for intensive roofs. It has been confirmed that the substrate can act as a source of phosphorus occurring in leachate from green roofs. It has been found that the P-reactive drainage layer of Polonite® in thickness of 2 and 5 cm reduces phosphate load in runoff. The load of phosphorus discharged from the columns amounted to 0.091; 0.032 and 0.02 mg P-PO4 for K1 (S:RM=10:1), K2 (S:RM=10:2) and K3 (S:RM=10:5). Layer of the substrate relative to reactive material layer of 10: 2 was considered as an optimal solution. In relation to the quality of water supplied an increase of pH and conductivity in runoff was observed. The P-reactive drainage layer and its thickness had no effect on these parameters. All the columns reduced water outflow by approximately 40% compared to the volume of simulated precipitation.

Adequacy Study of Biochar as Green Roof Material Using a Rainfall Simulator

Adequacy Study of Biochar as Green Roof Material Using a Rainfall Simulator

The Influence of Roof Cover Material on Gable Model to Climate Parameters - Case Study :RumahInstanSederhanaSehat (RISHA), PuslitbangPermukiman, Bandung

<div class="page" title="Page 1"><div class="layoutArea"><div class="column"><p><span>A roof should be able to prevent and reduce the radiationheat.It is more recommended if it gives a good effect in both prevention and reduction of heat. Through this research, the author wanted to know the influence of the roof covering material to gable roof style towards the climate parameters, such as temperature of humidity and heat radiation. Gable roof style is considered as more effective rather than others traditional roof style. The ability of heat reduction and humidity performances of the gable roof was tested by using Asbestos, Roof Tiles, Metal deck, and Green Roof covering material to RumahInstanSederhanaSehat (RISHA) in Centre for Housing Research and Development (PuslitbangPermukiman), Bandung. The variations of ceiling and non-ceiling were applied for knowing the result specifically in terms of the level of humidity and temperature in the room. By using quantitative descriptive method, Metal deck gave the fastest effect towards the temperature reduction, while Roof Tiles gave the best effect by using ceiling, and Green Roof gave the best effect by not using ceiling. Humidity aspect that gave the best effect occurred when using ceiling, either when using ceiling or not. Meanwhile, the lowest humidity happened when using Asbestos and Green Roof material. In the ability to reduce heat radiation, Green Roof had the best ability in reducing the heat or had worst ability in heat radiation, followed by Metal deck. </span>Meanwhile, Asbestos covering material had the best heat radiation ability.</p></div><div class="column"><p><span>Keywords: Roof Covering Material, Gable Roof Model, Climate (temperature, humidity, and heat radiation). </span></p></div></div></div>

THE INFLUENCE OF ROOF COVER MATERIAL ON GABLE MODEL TO CLIMATE PARAMETERS Case Study :Rumah Instan Sederhana Sehat (RISHA), PuslitbangPermukiman, Bandung

AbstractA roof should be able to prevent and reduce the radiation heat. It is more recommended if it gives a good effect in both prevention and reduction of heat. Through this research, the author wanted to know the influence of the roof covering material to gable roof style towards the climate parameters, such as temperature of humidity and heat radiation. Gable roof style is considered as more effective rather than others traditional roof style. The ability of heat reduction and humidity performances of the gable roof was tested by using Asbestos, Roof Tiles, Metal deck, and Green Roof covering material to RumahInstanSederhanaSehat (RISHA) in Centre for Housing Research and Development (PuslitbangPermukiman), Bandung. The variations of ceiling and non-ceiling were applied for knowing the result specifically in terms of the level of humidity and temperature in the room. By using quantitative descriptive method, Metal deck gave the fastest effect towards the temperature reduction, while Roof Tiles gave the best effect by using ceiling, and Green Roof gave the best effect by not using ceiling. Humidity aspect that gave the best effect occurred when using ceiling, either when using ceiling or not. Meanwhile, the lowest humidity happened when using Asbestos and Green Roof material. In the ability to reduce heat radiation, Green Roof had the best ability in reducing the heat or had worst ability in heat radiation, followed by Metal deck. Meanwhile, Asbestos covering material had the best heat radiation ability.Keywords: Roof Covering Material, Gable Roof Model, Climate (temperature, humidity, and heat radiation).

Assessing climate-adaptation effect of extensive tropical green roofs in cities

Many cities have inadequate green infrastructures and cannot benefit from ecosystem services brought by greenspaces. Global warming and urban heat island (UHI) effect impose a dual warming impact on cities, especially compact ones. Green roofs offer a plausible solution for climate adaptation. In compact humid-tropical Hong Kong, two green-roof and a control bare-roof plots were installed on a high-rise building. Precision sensors were installed along a holistic vertical temperature profile extending from outdoor air to roof surface, green-roof material layers, and indoor ceiling and air. Three apartments under the plots were kept vacant to monitor air-conditioning energy consumption. The comprehensive-systematic data allowed in-depth analysis of thermal performance of vegetation (Sedum and Perennial Peanut) and weather (sunny, cloudy and rainy) in summer. Intense solar radiation at Control plot triggered significant material heating, which in turn warmed near-ground air to intensify UHI effect and indoor space to lift energy consumption. Sedum plot with incomplete plant cover, sluggish transpiration and limited substrate moisture storage had feeble evapotranspiration cooling. The warmed roof passed heat to near-ground air and subsurface layers to impose a small indoor cooling load. Peanut plot with high transpiration rate can significantly cool foliage surface and near-ground air to ameliorate UHI. Its high moisture-holding capacity, however, can generate an appreciable heat-sink to push heat downwards and increase indoor cooling load. Practical hints on green roof design and management were distilled from the findings for application in Hong Kong and beyond and to contribute to climate-resilient cities.

Prospects of green roof technology for energy and thermal benefits in buildings: Case of Jordan

Heat transfer has a substantial impact on thermal comfort for indoor architectural spaces, which is mainly dependent on building envelopes. Improving the quality of indoor spaces means applying a climate-conscious design that is very beneficial in decreasing energy consumption in buildings.In this paper, a study based on thermal calculations and computer simulation is conducted to demonstrate the thermal benefits on energy saving as an approach to increase energy efficiency through green roof technology. The study focuses on roof surfaces as they account for a large portion of the insulation impact on built environments. A comparison between regular roof and green roof technologies was conducted to explore the effect of green roof materials on thermal transmittance and eventually on energy consumption of HVAC systems in buildings.

Effects of plant and substrate selection on thermal performance of green roofs during the summer

Green roof assemblies influence the total roof surface energy balance for a building. The energy balance for a green roof depends mostly on the selection of plants and substrates suitable for the building's location. This study measured thermal properties of common green roof materials and selected two types of plants and substrates to simulate transient thermal performance of different green roof assemblies. The selected plants and substrates have the highest and lowest reflectivity values to establish upper and lower bounds of thermal performance. The simulations use a previously developed green roof model including weather data for four cities representing different climate zones in the U.S. Based on the simulations, substrate heat fluxes and net radiation fluxes are compared for five days in July of the typical meteorological year. The results show that green roof assemblies receive net radiation fluxes that differ by 20%, and peak net radiation fluxes that differ by 16%, due to their different spectral reflectivity values. However, the substrate heat fluxes are similar for different green roof assemblies, as a roof insulation layer diminished this flux. Overall, the material selection of green roof assemblies is more important for buildings located in climate zone 4 or 5 than buildings located in climate zone 2 or 3, where limited water availability for evapotranspiration during hot, dry summers results in little thermal performance variability. Independent of the climate zones, simulation results show that the plant type has an important effect on the net radiation.