Assessment Of Light Green Roof Economics Benefits In Suzhou

With the accelerated process of urbanization today, the rapid development of the construction industry, on the one hand, improves the people’s living environment and standards. On the other hand, it resulted in a yearly energy consumption of buildings due to the rapid increase in building space and environmental problems caused by the lack of urban green land.This paper make a research involved in green building’s energy savings,Eco-city’s LID development,absorbing harmful air pollutants and many other aspects.Based on green roof building construction-14J206, this article discuss the economics benefits of light green roof to promote application in future Suzhou project. The main results are as follows:(1) The green roof can change heat transfer coefficient of the roofing building envelopment and has a huge impact on the building interior insulation in summer and winter. Simulated the indoor temperature corresponding to annual changes in the building combining actual measurement and simulation software, the indoor cooling was 0.98 to1.55 ℃ with June to August as the summer months; the green roof insulation effect was2.13 to 3.29 ℃ with November to next January as the winter months.(2) Green roof had an impact on building’s heating and cooling load in summer and winter by affecting indoor temperature. With annual energy consumption of ordinary roofing as a reference, it discussed the energy savings of green roof in four different approaches on Suzhou climatic conditions, which 100 mm light green roof energy saving economic benefits was 24.33 to 25.27yuan/ m~2 · a and 300 mm light green roof was 24.33 to25.27yuan/ m~2 · a,and which 100 mm insulating light green roof saving was 24.62 to25.33yuan/ m~2 · a and 300 mm insulating light green roof was 24.66 to 25.79yuan/ m~2 · a.(3) On the corresponding carbon emission standards for building energy and carbon saving, carbon-saving of green roof was estimated which 100 mm light green roof energy saving economic benefits was 50.34 to 50.39kg/ m~2 · a and 300 mm light green roof was49.03 to 49.74kg/ m~2 · a,and which 100 mm insulating light green roof results was 48.11 to48.34kg/ m~2 · a and 300 mm insulating light green roof was 47.20 to 47.96kg/ m~2 · a.(4) The green roof has a significant impact on the urban runoff. By determining the range of green roof runoff coefficient in Suzhou according to relative formulas and combining with the norms, the rainfall runoff peak reduction was 44.27% to 64.6% 。According to Beijing’s 2030 green roof construction rate and Shanghai’s 13 th plan of five-year national development,the light green roof can make a reduce from 6.73% to 8.42% on the total urban runoff.(5) Using the way of Market values and Shadow project, it can be easy for us to make an economic assessment of green roof ecological benefits. With the research data, the economic benefits of common green roof can make a balance with construction investment between 5.28 to 7.10 years. Compared with it, the balance year of green roof with insulation is between 8.44 to 10.84 years.(6)Based on payback period of 7years and research economic benefits,this article makes the amount of light green roof subsides in Suzhou which 100 mm light green roof energy saving economic benefits was 1.44 to 5.90yuan/ m~2 · a and 300 mm light green roof was 20.19 to 23.67yuan/ m~2 · a,and which 100 mm insulating light green roof saving was91.72 to 93.87yuan/ m~2 · a and 300 mm insulating light green roof was 108.42 to113.32yuan/ m~2 · a.