Forest Service/USDA Wood Innovations Grants
Recipient Point of Contact: Nicole K. Knobloch
Location: Arlington, Massachusetts
Summary
Building on successful work creating demand for mass timber as a climate solution in the Boston area through a 2019 Wood Innovation Grant, Olifant and a national group of AEC partners will do the same for three sister cities and their states/ surrounding regions: Atlanta, Minneapolis, and Denver. The goal is to enable each city to make mass timber a centerpiece carbon reduction strategy for the built environment and to be ready to offer a USFS Mass Timber Accelerator grant program to developers and/or other incentives for mass timber construction. Working in collaboration with AIA chapter partners, our AEC industry leaders will conduct regionally-based comparative studies on carbon benefits of local mass timber construction, cost and procurement considerations, forest sourcing, and current and potential U.S. mass timber manufacturing, nationally and regionally, developed into educational materials for use by AEC professionals and city planners. The overarching goal is to create robust, long-term demand for mass timber construction in these cities and nationwide that will encourage more U.S. mass timber manufacturing investment.
Australian Life Cycle Assessment Society conference
Research Status
Complete
Summary
The use of timber construction products and their environmental impacts is growing in Europe. This paper examines the LCA approach adopted in the European CEN/TC350 standards, which are expected to improve the comparability and availability of Environmental Product Declarations (EPDs). The embodied energy and carbon (EE and EC) of timber products is discussed quantitatively, with a case study of the Forte building illustrating the significance of End-of-Life (EoL) impacts. The relative importance of timber in the context of all construction materials is analysed using a new LCA tool, Butterfly. The tool calculates EE and EC at each life cycle stage, and results show that timber products are likely to account for the bulk of the EoL impacts for a typical UK domestic building.
Assessment and Optimisation of CFRP Reinforced Glulam Beams - A Feasibility Study in Design Stage Reinforcement Configurations for Pedestrian Bridge Applications
Many actions have been taken to decrease the operational energy use in buildings. However, with higher energy efficiency standards, the focus is increasingly shifting to energy demand for the production of building materials and the related greenhouse gas emissions. When moving towards zero emission buildings, the developments of more sustainable bearing structure are of interest. A six story housing complex was constructed in Gothenburg, Sweden in 2012 with a structure made of laminated veneer lumber floor elements and glue laminated beams and columns. The use of laminated veneer lumber has the advantage of being a light weight solution.
Building with wood in Norway is generally regarded as a carbon efficient solution, but the impact of additional materials such as glue and insulation can influence the overall results is of interest. Life cycle assessment is used as a tool to calculate the carbon footprint in the production of the main building materials of the structure. The goal of the assessment is to compare the wood structure as built with an equivalent steel and concrete structure and to optimise the use of materials. The scope of the assessment includes the foundation and elevator shaft, structural beams and columns and the floor elements. The results indicate that the steel and concrete alternative have about 35% higher greenhouse gas (GHG) emissions than the as built wood solution, but that almost half of the total emissions are related to the foundation and elevator shaft.
With the aim of evaluating the bond behaviour between glulam and carbon fibre reinforced polymer laminates strips, an experimental program using pull-out tests was carried, when the near-surface strengthening technique is applied. Two main variables were studied: the bond length and the type of pull-out test configuration. The instrumentation included the loaded and free-end slips, as well as the pullout force. Based on the obtained experimental results, and applying an analytical-numerical strategy, the local bond stress-slip relationship was determined. In this work the tests are described, the obtained results are presented and analysed, and the applicability of an inverse analysis to obtain the local bond law is demonstrated.
There has been no research to date exploring whether timber products can provide effective thermal capacitance in residential or commercial construction. This research is exploring the use of unique mass-timber products to provide a new form of thermal performance capacitance within the built fabric of new and existing homes. The development of mass timber products is a new paradigm in material and building science research in Australia, requiring the accounting for carbon emissions, carbon sequestration, material embodied energy and material thermal properties for this renewable resource. This paper focuses on the results from preliminary building simulation studies encompassing house energy rating simulations and a comparative analysis of embodied energy and carbon storage for a series of house plans in Australia.
Long service life, low maintenance requirements during service life reduce CO2-emissions. The use of wood for building purposes has the highest carbon mitigation potential, especially attributed to the high displacement factors and the long service life of products. The carbon mitigation of wooden building products is between 7.0 and 8.5 tCO2 per m³ of products and between 5.5 and 6.5 tCO2 per m³ of harvested wood respectively.
Background
There has been growing interest in the development of waste-specific decay factors for estimation of greenhouse gas emissions from landfills in national greenhouse gas inventories. Although engineered wood products (EWPs) and paper represent a substantial component of the solid waste stream, there is limited information available on their carbon dynamics in landfills. The objective of this study was to determine the extent of carbon loss for EWPs and paper products commonly used in Australia. Experiments were conducted under laboratory conditions designed to simulate optimal anaerobic biodegradation in a landfill.
Results
Methane generation rates over incubations of 307–677 days ranged from zero for medium-density fibreboard (MDF) to 326 mL CH4 g-1 for copy paper. Carbon losses for particleboard and MDF ranged from 0.7 to 1.6%, consistent with previous estimates. Carbon loss for the exterior wall panel product (2.8%) was consistent with the expected value for blackbutt, the main wood type used in its manufacture. Carbon loss for bamboo (11.4%) was significantly higher than for EWPs. Carbon losses for the three types of copy paper tested ranged from 72.4 to 82.5%, and were significantly higher than for cardboard (27.3–43.8%). Cardboard that had been buried in landfill for 20 years had a carbon loss of 27.3%—indicating that environmental conditions in the landfill did not support complete decomposition of the available carbon. Thus carbon losses for paper products as measured in bioreactors clearly overestimate those in actual landfills. Carbon losses, as estimated by gas generation, were on average lower than those derived by mass balance. The low carbon loss for particleboard and MDF is consistent with carbon loss for Australian wood types described in previous studies. A factor for carbon loss for combined EWPs and wood in landfills in Australia of 1.3% and for paper of 48% is proposed.
Conclusions
The new suggested combined decay factor for wood and EWPs represents a significant reduction from the current factor used in the Australian greenhouse gas inventory; whereas the suggested decay factor for paper is similar to the current decay factor. Our results improve current understanding of the carbon dynamics of harvested wood products, and allow more refined estimates of methane emissions from landfills.
This is a pilot project to establish an embodied carbon footprint performance target for new multi-unit residential building (MURB) construction.
This project has demonstrated that compiling the bills of materials of multiple buildings and deriving a useable benchmark based on this information is methodologically and practically possible. The report presents several recommendations on how to proceed with this important initiative based on the project findings.
The need to lower the embodied carbon impact of the built environment and sequester carbon over the life of buildings has spurred the growth of mass timber building construction, leading to the introduction of new building types (Types IV-A, B, and C) in the 2021 International Building Code (IBC). The achievement of sustainability goals has been hindered by the perceived first cost assessment of mass timber systems. Optimizing cost is an urgent prerequisite to embodied carbon reduction. Due to a high level of prefabrication and reduction in field labor, the mass timber material volume constitutes a larger portion of total project cost when compared to buildings with traditional materials. In this study, the dollar cost, carbon emitted, and carbon sequestered of mass timber beam–column gravity system solutions with different design configurations was studied. Design parameters studied in this sensitivity analysis included viable building types, column grid dimension, and building height. A scenario study was conducted to estimate the economic viability of tall wood buildings with respect to land costs. It is concluded that, while Type III building designations are the most economical for lower building heights, the newly introduced Type IV subcategories remain competitive for taller structures while providing a potentially significant embodied carbon benefit.
