This is a four-part blog post on CBA-BIM. First I’ll introduce the concept and benefits of CBA-BIM. Then I’ll discuss distance decay functions and how they link economics and geography. Then I’ll present an example of transit infrastructure and social equity. Finally I’ll talk about how CBA-BIM can be used for informed, socially equitable, and defensible sustainable infrastructure and resiliency decisions.
Building Information Modeling (BIM) is increasing the transparency and consistency of data in the planning, design, and operations phases of infrastructure projects . Economic Cost-Benefit Analysis (CBA) is currently used on infrastructure projects to decide whether to proceed and, occasionally, which alternatives to design. Marrying CBA with BIM has tremendous potential to help in making sustainability decisions related to infrastructure and resiliency. This paper (in four posts) shows how CBA-BIM can produce better estimates of the social value of infrastructure, characterized in the Quality of Life category in Envision,TM, as well as addressing issues of social equity. CBA-BIM has the potential to measure the “resiliency of physical infrastructure across the full economic, social, and environmental dimensions of sustainability” 
Three innovations in the economic analysis have led to the ability to include Cost-Benefit Analysis (CBA) in Building Information Modeling (BIM) models. First, CBA’s methodology, input data, and outputs are being standardized . Second, risk analysis and meta-analyses  mean that uncertain or controversial inputs can be used. Finally, multiple account CBA allows for an understanding of all stakeholders’ benefits.
A linking of CBA’s valuation methodologies, such as willingness to pay, damage costs, and travel cost to a geographical information system (GIS), allows for CBA to add new data layers to a BIM model. CBA-BIM gives architects, engineers, designers, and planners access to a powerful tool that can help them decide what to build, how to build it, what the risks are, and who benefits.
The Benefits of CBA-BIM
The benefits of using CBA inside BIM are that: BIM defines relationships between objects and keep changes consistent and coordinated. So, as the design changes, so can the economic costs, benefits, and risks. BIM can show the economic business case for design alternatives while maintaining constraints such as building codes, design or safety criteria, and local or community standards. Also, BIM is visual, enabling better analysis, simulation, and communication. When combined with risk-based multiple account cost-benefit analysis, it becomes a powerful stakeholder visualization tool.
Many of the benefits that are captured in the EnvisionTM’s Quality of Life category are quantified and monetized in the Economic Companion Tools to EnvisionTM such as the Business Case Evaluator (BCE).
Extending the monetization of the EnvisionTM credits to give them a geographical dimension in CBA-BIM further builds EnvisionTM’s usefulness to the infrastructure community.
To Come …
In subsequent posts I’ll look at
- Distance decay functions – Linking Economics and Geography;
- An Example: Transit Infrastructure and Social Equity; and,
- CBA-BIM for Informed, Socially Equitable, and Defensible Sustainable Infrastructure & Resiliency Decisions
 Envision 2.0 A Rating System for Infrastructure – Guidance Manual, Zofnass Program for Sustainable Infrastructure at the Harvard University Graduate School of Design and the Institute for Sustainable Infrastructure.
Some examples of standardization from U.S., E.U., Canada, and Australia: US department of Transportation, Benefit-Cost Analyses Guidance for TIGER Grant Applicants – TIGER BCA Guidance (2014) [Link] and TIGER BCA Resource Guide (2014) [Link]; US department of Transportation, Federal Highway Administration. 2013. Benefit-Cost Analysis – Asset Management [Link]; European Commission.2008. Guide to Cost-Benefit Analysis of Investment Projects [Link]; Canadian Cost-Benefit Analysis Guide: Regulatory Proposals 2013 [Link]; Australia Department of Finance and Deregulation, Office of Best Practice Regulation, Best Practice Regulation Handbook – Appendix E. Cost-benefit analysis, 2013 [Link]
 “a meta-analysis refers to methods that focus on contrasting and combining results from different studies, in the hope of identifying patterns among study results, sources of disagreement among those results, or other interesting relationships that may come to light in the context of multiple studies.” Meta-analysis From Wikipedia, the free encyclopedia, [Link]
 Triple Bottom Line Business Case Analysis for Infrastructure Planning and Design – [Link]
 The Business Case Evaluator for Stormwater Management Best Management Practices Released [Link]; Business Case EvaluatorTM Documentation and Spread Sheets [Link]