BIM extension for the sustainability appraisal of conceptual steel design

Contemporary advancements in Information Technology and the efforts from various research initiatives in the AEC industry are showing evidence of progress with the emergence of building information mod- elling (BIM). BIM presents the opportunity of electronically modelling and managing the vast amount of information embedded in a building project, from its conception to end-of-life. Researchers have been looking at extensions to expand its scope. Sustainability is one such modelling extension that is in need of development. This is becoming pertinent for the structural engineer as recent design criteria have put great emphasis on the sustainability credentials in addition to the traditional criteria of structural integrity, constructability and cost. With the complexity of designs, there are now needs to provide deci- sion support tools to aid in the assessment of the sustainability credentials of design solutions. Such tools would be most beneficial at the conceptual design stage so that sustainability is built into the design solu- tion starting from its inception. The sustainability of buildings is related to life cycle and is measured using indicator-terms such as life cycle costing, ecological footprint and carbon footprint. This paper proposes a modelling framework combining these three indicators in providing sustainability assessments of alterna- tive design solutions based on the economic and environmental sustainability pillars. It employs the prin- ciples of feature-based modelling to extract construction-specific information from product models for the purposes of sustainability analysis. A prototype system is implemented using .NET and linked to the BIM enabled software, Revit StructuresTM. The system appraises alternative design solutions using multi-crite- ria performance analysis. This work demonstrates that current process and data modelling techniques can be employed to model sustainability related information to inform decisions right from the early stages of structural design. It concludes that the utilized information modelling representations – in the form of a process model, implementation algorithms and object-based instantiations – can capture sustainability related information to inform decisions at the early stages of the structural design process

The Discount Rate in the Evaluation of Project Economic-Environmental Sustainability

The debate about project economic sustainability evaluation from a life cycle perspective focused on the conventional Life Cycle Costing (LCC). Despite the potentialities of the approach for evaluating design options at different scales (building/system/component/material), some limits emerge due to the neoclassical nature of the economic principles on which it is founded. The most important aspect of this debate is the necessity to clarify how to deal with environmental costs in the calculation, particularly in the case of public/PPP interventions. Two research topics emerge for strengthening the capability of LCC to deal with environmental components: (1) the LCC and environmental quantitative analysis (using Life Cycle Assessment) joint application; (2) the integration of the environmental dimension into the microeconomic approach, using appropriate discount rates. As known, these last are particularly relevant for public projects, in which the time value of money issue becomes crucial in presence of long lifespan analyses and economic objectives. Thus, the purpose of this paper is to explore alternative discounting modalities, for identifying the preferable one, towards an “environmental LCC model”. The research domain is therefore on the limits of LCC in dealing with environmental cost components, at the time being poorly studied by the scientific literature: this point represents the missing link which form the basis for the research problem to be addressed. The research design is focused on the investigation of environmental hurdle rate technique and the escalation rate approach, as alternatives to the standard “time preference” (financial) one. The LCC and the global cost are selected as the main tool for the analysis, which is founded on an empirical research methodology. The results, obtained by simulations on a case study (two alternative technological components), confirm the relevance of the discount rate effect on the Global Cost calculation by modelling some of the potential impacts of building components on the environment, e.g., the expectations of technological development over time. By the environmental hurdle rate, the results can even change the final preferability ranking obtained using financial rates. The value of the work consists of growing the debate on the topic and supporting environmentally responsible investment decisions in the building construction sector (new-build/retrofit of existing assets)

Sustainable Public Procurement in the Building Construction Sector

Considering that in the E.U. public procurement in the construction sector is highly represented, the Directive 2014/24/EU is implemented for harmonizing procurement processes across European countries. The Directive is transposed in Italy, through the Sustainable Public Procurement (SPP) national action plan, for supporting public procurement and public–private partnership (PPP) interventions. SPP is founded on two pillars: according to an economic viewpoint, the financial efficiency is the key aspect to verify, and, according to a sustainability viewpoint, externalities are a key element in the environmental evaluation, despite the fact that their monetary quantification into the global cost calculation is quite complex. Thus, this work aims to explore a methodology for the joint evaluation of economic–environmental sustainability of project options, in the tender evaluation phase of the SPP. The methodology is based on the life cycle costing (LCC) and CO2 emissions joint assessment, including criteria weighting and uncertainty components. Two alternative technologies—a timber and an aluminum window frame—are assumed as a case for a simulation, implemented with the software “Smart SPP LCC-CO2 Tool” (developed through the research “Smart SPP—Innovation through sustainable procurement”, supported by Intelligent Energy Europe). The simulation demonstrates that the methodology is a fast and effective modality for selecting alternative options, introducing sustainability in the decision-making process. The work is a contribution to the growing literature on the topic, and for giving support to subjects (public authorities and private operators) involved in public procurement processes/PPP interventions

Does Green Public Procurement lead to Life Cycle Costing (LCC) adoption?

Life Cycle Costing (LCC) is rarely used in public procurement and public institutions have yet to fully understand its potential value for sustainable procurement. The new European Directive on Public Procurement is, however, designed to position LCC as central to sustainable sourcing. Although previous studies have identified positive correlations between Green Public Procurement Policies (GPP) and LCC, it is still unclear how public institutions can further adopt LCC practices by leveraging their experience of green sourcing. In this study an organizational learning theoretical perspective is taken to investigate the circumstances under which public administrations’ experience of GPP – considered as a way of integrating the dimension of environmental sustainability into the sourcing process – stimulates their LCC learning and capabilities – considered as a way to include the sustainability economic dimension. The goal is to understand if the adoption of GPP can stimulate the internalisation of LCC in public tenders. A multinomial logistic regression was conducted using a sample of 120 public administrations located in different countries. The results show that experience of GPP stimulates the internalisation of LCC at a public level, but only under specific conditions. The study contributes to the Sustainable Supply Management literature, being one of the first studies in the field adopting an organizational learning theoretical lens to review the role of experience as significant opportunity to develop capabilities. It also contributes to the organizational learning theory, by confirming that experience can aid learning but only in specific environmental contexts