Incentive schemes for green building promotion: transaction costs consideration of Hong Kong case

OLD Housing Quality and Process Innovatio

Floor area concession incentives as planning instruments to promote green building: A critical review of international practices

Gross Floor Area (GFA) concession scheme, as a planning incentive, is developed from the notion of “make developers pay” in UK in 1990. It rewards developers additional GFA in exchange for public amenities so that government could save that amount of money. This paper carries out a review of GFA concession scheme in Hong Kong and Singapore to synergize the key features and success factors of its implementation. Reasons for its effectiveness were discussed from the perspective of political, economical, and business issues. Based on case studies, the key features of “Floor Area Concession Schemes” are discussed, including 1) very effective in places with high land value; 2) influencing built environment positively and negatively; 3) ensuring the buildings get certified by green building (GB) rating system. This paper identifies key success factors, comprising 1) common goal but different interests shared by developers and governments; 2) a bonus cap; 3) regular review and revision of the scheme; 4) links between planning objectives and GB technology and design practice, which will be discussed. These help formulate a general approach or model of “Floor Area Concession Schemes” for promoting green building.OTBArchitecture and The Built Environmen

Challenges in Delivering Green Building Projects: Unearthing the Transaction Costs (TCs)

Delivering green building (GB) projects involve some activities that are atypical in comparison with conventional buildings. Such new activities are characterized by uncertainty, and they incur hidden costs that have not been expected nor are they readily appreciated among the stakeholders. This paper develops a typology and chronology to examine the new activities that are associated with transaction costs (TCs) in the real estate development process (REDP) of green building. Through in-depth interviews with representatives from the major developers in Hong Kong who have experiences in GB practice, this study aims to unearth TCs involved at the critical stages of the REDP. Apart from reconfirming the early project planning stage as the most critical in the consideration of TCs, the study results also identified “extra legal liability risk of the GB product” as the major concern for any GB developer in Hong Kong. The key additional activities that bring significant TCs in developing GB are identified and compared to their traditional counterparts. In turn, project managers not only have to pursue overall cost management whilst winning more business, but they also have to pay particular attention to sustainability in order to minimize hidden societal costs. The study also provides a reference for governments and professionals that will aid in forming policy as well as advance the practice of the GB market by optimizing the societal costs.OTBArchitecture and The Built Environmen

Improving the Supply Chain of Housing Industrialization from Transaction Costs Perspective: A Literature Review

Sustainable development has been the focus of all major industries in the world, especially in the construction industry. As one of the sustainable construction modes, housing industrialization (HI) is now absorbing a growing number of attentions that lead the industry to go green. However, the implementation of HI in China is far from satisfactory due to its low economic efficiency. This paper attempts to improve the HI supply chain from a new perspective-transaction costs (TCs). First, it provides an objective understanding of status quo of HI in particular in China. Then, the study outlines the basis of TCs theories and supply chain management theory, compiling literature review of the application of TCs and supply chain management in other fields to states the feasibility oftheir application in HI area. A theoretical framework is developed to explain the relationships and overlaps among these three areas. Analysis of the state of research in application of TCs in HI supply chain management is expected to help optimized the governance structure of HI supply chain.OLD Housing Quality and Process Innovatio

Modeling framework for fracture in multiscale cement-based material structures

Multiscale modeling for cement-based materials, such as concrete, is a relatively young subject, but there are already a number of different approaches to study different aspects of these classical materials. In this paper, the parameter-passing multiscale modeling scheme is established and applied to address the multiscale modeling problem for the integrated system of cement paste, mortar, and concrete. The block-by-block technique is employed to solve the length scale overlap challenge between the mortar level (0.1-10 mm) and the concrete level (1-40 mm). The microstructures of cement paste are simulated by the HYMOSTRUC3D model, and the material structures of mortar and concrete are simulated by the Anm material model. Afterwards the 3D lattice fracture model is used to evaluate their mechanical performance by simulating a uniaxial tensile test. The simulated output properties at a lower scale are passed to the next higher scale to serve as input local properties. A three-level multiscale lattice fracture analysis is demonstrated, including cement paste at the micrometer scale, mortar at the millimeter scale, and concrete at centimeter scale.Railway EngineeringMaterials and Environmen

Modeling fracture behavior of cement paste based on its microstructure

Concrete is a composite construction material, which is composed primarily of coarse aggregates, sands and cement paste. The fracture processes in concrete are complicated, because of the multiscale and multiphase nature of the material. In the past decades, comprehensive effort has been put to study the cracks evolution in concrete, both experimentally and numerically. One essential step to solve the multiscale modeling problem for concrete is to figure out the relation between the mechanical performance and its microstructure. As cement paste is the most complicated component in concrete, it is investigated in detail in this paper. The modeling procedure developed for cement paste is also valid for mortar and concrete, but at a higher scale. Two numerical models are involved in this procedure: the HYMOSTRUC3D model to simulate the microstructure of cement paste, and the 3D lattice fracture model to evaluate the mechanical performance of the microstructure.Structural EngineeringCivil Engineering and Geoscience

An Alternative Model to Determine the Financing Structure of PPP-Based Young Graduate Apartments in China: A Case Study of Hangzhou

Public-private partnerships (PPP) can be employed to provide public rental housing for young graduates, which has been urgent to achieve social sustainability in China. However, few studies have been conducted to investigate the financing structure of PPPs, particularly the ratio of private investment, which is important in initiating a PPP project. This study develops a robust model to determine the financing structure through considering the uncertainties in operation. A case study in Hangzhou demonstrates the process of the model. The relevant findings provide private investors and the local government with effective references for negotiating the financing structure of a PPP project.OTBArchitecture and The Built Environmen

3D Simulation of micromechanical behavior of cement paste

Numerical modeling of fracture processes of brittle materials, such as cement paste, mortar, concrete and rocks, started in the late 1960s when the discrete and smeared cracking models were introduced. In the 1990s, Schlangen and van Mier proposed another numerical model to compensate the drawbacks of the discrete and smeared cracking models, which is called lattice fracture model. From then on, plenty of investigations were conducted to exploit various applications of lattice fracture analysis, and this contribution is one of them. This paper studies the fracture process of cement paste at microscale, especially the tensile strength, elastic modulus and cracking due to external mechanical loads. The study is based on the microstructure of hardening cement paste and attempts to reveal the relationship between the microstructure and its global performance. Moreover, the crack propagation during the fracture process is also investigated in detail. In this paper, the microstructure of hydrating cement paste is simulated by HYMOSTRUC3D first, and then it is converted into a voxel based image. In the next step, a lattice network is created and the local mechanical properties are mapped from the simulated microstructure. After that, the fracture process is simulated using lattice analysis to obtain the load-displacement diagram and crack propagation. A series of numerical experiments are carried out to illustrate the influences of various input parameters, for instance, the degree of hydration, the Blaine value of cement and the water/cement ratio.Structural EngineeringCivil Engineering and Geoscience

Multiscale lattice fracture model for cement-based materials

Cracking in cement-based materials is usually not easy to predict, because of the complexity of their microstructures. Concrete is a composite material of mortar and coarse aggregates, and mortar consists of cement paste and sands. The fracture processes in these materials are related, and this paper aims to reveal the relationship by developing a multiscale model using lattice approach. Lattice fracture model was proposed and applied to simulate the fracture processes in concrete in the early 1990s. Afterwards it gained extensive investigations as it can reproduce the crack patterns observed in laboratory. The lattice model can also simulate the mechanical properties of cementbased materials, such as Young's modulus, tensile strength and fracture energy. In this paper, a multiscale lattice fracture model is proposed, which can connect the fracture behavior of cement paste at microscale to the mechanical properties of mortar at mesoscale, and eventually to the performance of concrete at macroscale. The upscaling technique in this model is an implementation of the multi-level homogenization concept.Structural EngineeringCivil Engineering and Geoscience

Influences of mineral composition of cement on the mechanical properties of cement paste

Structural EngineeringCivil Engineering and Geoscience