Construction Industry 1

LOCATION: 2306
08:30 Jeremy GregoryTravis Reed MillerJoshua HesterCarla Rodrigues and Randolph Kirchain

Streamlining residential building LCA via probabilistic underspecification

ABSTRACT. Traditional life-cycle assessment (LCA) is time, data, and resource intensive. For complex systems like residential buildings, these demands mean that most LCAs are only executed in the later design stages when most of the design decisions have already been made. Even in the late design stage, there are often data gaps that lead to uncertainty in the results.

This presentation will demonstrate the use of a probabilistic underspecification methodology to streamline comprehensive residential building LCA (including both embodied and use phases) as a means of reducing the expense and uncertainty in building LCA. The originality of the work is that the streamlined methodology requires significantly less effort than traditional LCA methodologies while maintaining a rigorous quantification of uncertainty and comprehensive scope, and enabling identification of key parameters that can reduce uncertainty.

An integrated methodology combining a probabilistic underspecification LCA approach and a streamlined use phase energy calculation model was developed and applied to US residential buildings. The TRACI 2.0 impact assessment method is used to illustrate the performance of this approach. Data describing the impact of building materials and systems as well as the attributes describing embodied and use-phase performance were categorized into four levels of specificity, Level 1 (L1) to Level 4 (L4), with L1 being the most underspecified and L4 as the most specified. A series of typical US residential buildings were analyzed at various levels (including hybrid) of specification. A statistical analysis was conducted to identify the most influential attributes (with the highest contribution to variance).

The selected attributes were resolved at L4 resolution of specificity to see how much improvement in fidelity of the impact estimate can be achieved. Preliminary results show that by specifying less than five key building attributes the fidelity of the estimate is similar to a fully-specified LCA. The coefficient of variation (COV) decreases from 37% to 8% for the total life-cycle impacts. The embodied impacts COV decreases from 148% to 52% and the use phase energy COV decreases from 28% to 7%.

The methodology can be used in the early stages of the design process and thus, can be used to quantify the environmental impacts of design decisions, including uncertainty, even when minimal information has been specified.

08:45 Penny Martyn and Rob Sianchuk

Integrating LCA into UBC Green Building Design Guidelines and Policy
SPEAKER: Penny Martyn

ABSTRACT. UBC is keen to integrate LCA in green building policy, but what is the best way? In 2014, Civil Engineering students worked with instructor Rob Sianchuk and UBC’s green building manager Penny Martyn to address this question by providing research on how best to include LCA in an upcoming UBC green building policy update.

The project was developed with three goals, including [1] To rationalize the integration of environmental life cycle assessment (LCA) in UBC building design guidelines, policy and operations, [2] To report on the UBC LCA Database and where it can be used by UBC sustainability programs, and [3] To propose how UBC could approach the implementation of LCA in building design and operations.

The resulting research developed by the students was delivered as a presentation with accompanying reports. Key findings concluded that: [1] Inclusion of LCA aligned well with existing initiatives, which primarily aim to reduce GHG emissions and resource use [2] Available UBC building LCA studies provide initial environmental impact reduction strategies and performance benchmarks, and [3] Recommended approaches to institutionalize LCA should consider use of LCA modeling tools, databases, decision making methods, key lessons learned and potential engagement strategies.

This project has made a significant contribution to advancing the integration of LCA findings and processes in UBC green building policy by performing a gap analysis of current policy and providing a range of suggested strategies. Additionally the project has contributed to the evolving framework for LCA studies of major buildings on campus. Another significant outcome has been the unique experience-based learning gained by the students, wherein they have gained hands-on experience with LCA and envisioned solutions to current challenges that extend beyond UBC campus.

Over the past ten years, policy at UBC has progressed from simply promoting single attribute materials (for example recycled content materials) to starting to incorporate lessons learned from LCA research as well as building LCA studies. Areas of current implementation include prioritizing lower impact materials and in particular using wood as a building structure (shown to have significantly less impact in a range of impact categories). Future implementation will include a more rigorous approach with the development of metrics related to LCA.

09:00 Yannick LessardPierre BlanchetCaroline Frenette and Ben Amor

Environmental life cycle impacts and LEED scores variations as a function of material choices – The Case of a real scale commercial building
SPEAKER: Ben Amor / Presentation

ABSTRACT. Building sector’s environmental footprint is significant in Canada. In order to reduce the environmental impacts of buildings, many available certification systems have been proposed, such as The Living Building Challenge (LBC), Leadership in Energy and Environmental Design ® (LEED) and Passive House. Some of these certifications focus on specific stages (ex. The use phase), and others have a broader scope. However, most of them do not necessarily take into account the interconnectivity of different life cycle stages (ex. Pollution displacements).

The objective of this work is to evaluate the variations in the environmental life cycle impacts (ELCI) and LEED v4 certification scores of a LEED-certified commercial building. These variations will be assessed based on the consequences of selecting different materials.

To meet this objective, a six-storey commercial building (Quebec, Canada) was selected as a case study. The ELCI are assessed using Simapro 8 software, Ecoinvent 3.1 database and Impact World + method. The ELCI of the building is modeled and its LEED v4 score is evaluated as a first step. Using these results based on main contributors, the case study scenario is then modified with different materials to draw up different scenarios. Finally, the ELCI and the LEED v4 score of these alternative scenarios are calculated and compared against the case study scenario.

Preliminary results already show the significant contribution of the production phase of the commercial building in contrast with previous publications in the field (the latter showing the importance of the use phase). The renewable character of the used energy in Quebec context mainly explains this exception. Forthcoming results will help in quantifying the potential variations of the ELCI and LEED v4 certification score according to building materials selections. Consequently, this will help the industry in its efforts to make better material choices. In addition, these results will provide some answers to the extent to which LEED v4 certification system should be regionalized in the context of the province of Quebec.

09:15 Nicholas SanteroVivian DienJames Vallette and Rebecca Stamm

Building Health and Environmental Impacts: A Common Product Approach

ABSTRACT. Life cycle assessment (LCA) is increasingly becoming part of the building design process. Architects, engineers, and owners are requesting whole-building LCAs and environmental product declarations (EPDs) to help establish the environmental footprint of their buildings. In parallel, these stakeholders are also collecting and evaluating building material health hazards, using mediums such as health product declarations (HPDs) and GreenScreen assessments. For both environmental and health burdens, two challenges persist: the lack of publicly available declarations and consistent reporting and methods. These challenges diminish the utility of LCA and health hazard analysis in affecting the building design process, particularly during early design.

A “common product” approach can be used to resolve the lack of data and inconsistency challenges for the purposes of early design decisions. Many of the key building materials and products can be simplified into a list of material contents that are roughly representative of an average, or common, product. These products can then be evaluated for their environmental and health impacts using consistent methods. This presentation will review the process for creating a draft common products list and the associated environmental and health burdens. Environmental impacts are evaluated using LCA (following 14040/44) and health burdens are evaluated through the Pharos library. Part of this review will also examine the challenges of combining LCA and health hazard data and research. The results will demonstrate the power of using common products, rather than actual products, to inform early design decisions and subsequent product specifications.