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Berkeley Lab Building Materials Pathways (B-PATH) Model

Introduction

Developed by researchers at Lawrence Berkeley National Laboratory (LBNL), the Berkeley Lab Building Materials Pathways (B-PATH) Model aims to enhance environmental decision-making in the commercial building LCA, design, and planning communities through the following key features:

1) Modeling of discrete technology options in the production, transportation, construction, and end of life processes associated U.S. structural building materials.  While there have been a number of stand-alone LCAs of commercial buildings and their materials, it is often difficult to transfer the results of these studies to assessments of real-world buildings.  Specifically, the environmental impacts of structural materials for a given job site will depend in part on the technology characteristics of local and regional supply chains; these characteristics might differ from the “average” technology assumptions used in many building LCA studies and databases.

2)  Modeling of energy supply options for electricity provision and directly combusted fuels across the building life cycle.  Most LCA models allow for some user-defined energy supply assumptions.  However, often the LCI data in such models are not sufficiently disaggregated into unit process technologies, whose energy use and fuel options (e.g., alternative fuels or fuel switching) can vary in practice.  B-PATH allows for user-defined energy supply at the process technology level, which provides greater flexibility for modeling regional and production system energy supply variations for structural materials.

3)  Comprehensiveness of relevant building mass and energy flows and environmental indicators to ensure that B-PATH’s discrete technology modeling approach allows for consideration of a range of environmental impacts in materials selection, and for different building elements.

4)  Ability to estimate modeling uncertainties through easy creation of different life-cycle technology and energy supply pathways for structural materials, and easy consideration of different  methodological assumptions (e.g., system boundaries and allocation protocols), which can serve as bounding scenarios on environmental impacts.

5)  Encapsulation of the above features in a transparent public use model, which can be assessed and refined by the stakeholder community, expanded to include new technology options as they emerge over time, and can offer a fully citable public data resource.

Model development was focused on life-cycle pathways for three major structural materials options for commercial buildings: (1) reinforced concrete; (2) steel; and (3) lumber.  The current version of B-PATH is targeted at low-rise construction (typically defined as 2-5 floors) due to the predominance of this building form in the U.S. commercial sector.

Download the B-PATH Model and Report

B-PATH is available as a Microsoft Excel file, which can be downloaded by clicking here.

The B-PATH project report can be downloaded by clicking here.
B-PATH Development Team

Alexander Stadel, Drexel University
Petek Gursel, University of California, Berkeley
Eric Masanet, Lawrence Berkeley National Laboratory and University of California, Berkeley

Contact Information

Questions about the B-PATH model should be directed to:

Eric Masanet, Ph.D.
Staff Scientist
Energy Analysis Department
Environmental Energy Technologies Division
Lawrence Berkeley National Laboratory
Building 90R4000
Berkeley, California, USA  94720
Phone: 1.510.486.6794
Fax: 1.510.486.6996
Email: ermasanet@lbl.gov