Streamlining Whole Building Life Cycle Assessment of Mass Timber Buildings

芝麻小事的新资源如何指导设计团队对大规模木结构建筑的WBLCA感兴趣

设计界已经接受了使用整个建筑生命周期评估(WBLCA)来量化和比较建筑的环境影响. 然而, 对野生野生动植物保护区采取统一办法的详细标准仍在制定中, leaving designers needing clearer direction during the assessment process. To solve this, we developed a resource to help untangle the WBLCA process. 

Part of 芝麻小事’ carbon initiative, 大型木结构建筑无砌块砌筑的考虑与工作表, 旨在概述国际标准中对生命周期评估(LCA)的要求，并就如何使用市售的LCA工具对大型木结构建筑执行wblca提供指导. Our ongoing work with KL&一个工程师 & 2021年与我们一起撰写了普拉特十五WBLCA的建筑商也帮助塑造了这份文件.

就大型木结构建筑设计而言，本文件的目的是什么? 

阿什利礼物 The world of LCAs is a bit like the Wild West right now. 人们对了解我们的建筑对环境的影响有着极大的兴趣, we want to quantify that impact so we can work to reduce it. Because this is a relatively new field, and because of the urgency of our climate crisis, many people are working to rapidly develop standards, 规则, 指导, and best practices. 这些努力很棒，但可能导致混乱和相互矛盾的信息. At the same time, 当前的许多标准没有提供许多设计人员所寻求的专一性, especially when looking at comparative WBLCAs of wood buildings. We’re not trying to create another LCA standard or guide document, 相反，我们将引导设计师逐步完成符合iso标准的LCA过程，并确定木结构背景下的关键决策点.

工作表如何帮助团队对大型木结构建筑进行WBLCA? 

AC: 在理论上, doing a WBLCA sounds very straightforward: Do a material takeoff, plug those numbers into your LCA tool, run the analysis, and boom—you’re done! But in practice, quite a few questions arise early in the process, 这样的事情, Do I include finishes? What about foundations? How do I develop an equivalent alternative design? 理解LCA工具中“内置”的内容与设计师需要做出的决策也可能令人困惑. 工作表的目的是概述这些决策点，以便设计师在LCA的规划阶段更好地了解情况，并在整个LCA过程中为如何回答大型木结构建筑的这些问题提供指导. 

的样本 工作表 available to design teams

What common question or issue does this answer for designers?

AC: 执行结构化WBLCA的一个更具挑战性的方面是定义范围. Again, something that sounds like it would be relatively straightforward. But in my experience, LCA项目团队花费大量时间讨论哪些材料, 程序集, and systems will be included, 在LCA过程开始的时候，很难预测所有的问题. Are we only studying structural framing, or are we also looking at exterior enclosures and non-structural walls? Are we including any architectural finishes?  

在对大型木结构建筑和传统建筑(如钢结构或混凝土)进行LCA比较时，准确定义材料范围变得更加重要. 这些结构系统之间的主要内在差异超出了框架成员本身. 例如，我们需要确保所有的设计方案都具有相同的防火性能. For a mass timber building, 这可能意味着我们需要包括额外的木材体积来满足木炭评级, whereas for a steel building, we might need to include spray fireproofing material. 这张工作表有助于列出许多不同之处，这样设计师就可以对不同的设计进行比较.

对于更全面的WBLCA工作表，您有什么工具推荐使用吗? 

AC: I am often asked which LCA tool is best and which tool(s) to use.  We do recommend that designers use a whole-life LCA tool; that is, 覆盖所有生命周期阶段，而不是仅覆盖从摇篮到闸门(A1-A3)或从摇篮到施工闸门(A1-A5)阶段的基于epd的工具. Commercially available LCA tools commonly used in the U.S. include Athena, tallyLCA, and One Click LCA. 经常, 设计团队将根据工具适合其既定工作流程的容易程度来选择工具, which is arguably the most important factor. 团队需要选择他们最有可能使用的工具，因为第一步才刚刚开始. 然而, 还有许多其他的区别——从使用的数据到编程到工具的假设. I always say that one tool is not better than another, 但重要的是，用户要知道他们正在使用的工具是如何工作的，并完全理解它的结果. 

What else to know 

AC: The idea behind the fillable PDF was to create a practical, useful resource that helps project teams complete comparative LCAs. It can be used to help guide project team meetings, document important scope decisions that were made, and facilitate writing a comprehensive LCA report. Most importantly, 这是为了确保准确地捕捉到大量木结构建筑的所有独特属性，以便与更传统的建筑材料进行准确的比较. 

如果您的项目使用工作表来帮助指导大规模木材项目的比较WBLCA, we’d love to hear about it.

Send Ashley a note at: 阿什利.cagle@landairy.com.

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