Seeking Advice on Best Practices for Using Tally

I will share a few items quickly, but I am happy to share more later... Here is a whitepaper we created on EC with case studies. It has the attached EC Workflow diagram in it https://issuu.com/lakeflato/docs/carbon_journal_entry_final_r The other image attached shows an EC design option effort (EC Design Options.png). Tally v. TallyCat TallyCat (free) will eventually replace Tally (not free) from what I understand. We still use Tally, which works directly in Revit and includes additional data like acidification and eutrophication. However, Tally has a fixed product database, whereas TallyCat uses EPDs. So, measuring the benefits of DLT on the Hotel Magdalena (one of the case studies) was tricky. Other tools: We recently started using OneClick LCA, which also has challenges. But it is a very robust tool so far. We are using this for our ILFI Zero Carbon certification for our own office remodel. Autodesk is working on an EC tool that uses Building Transparency's open-source EDP database (they recently presented together at Autodesk University). https://blogs.autodesk.com/aec/2023/02/15/autodesk-insight-tech-preview-now-available-carbon-insights/  

Interesting questions and ones we are still evolving answers on as I suspect most are. Typically a true whole building LCA in Tally happens sometime in CDs when the design is set, model is detached, etc and of course too late for significant changes - but good for LEED credit and reflecting overall savings from earlier decisions. I will say we’ve done enough WBLCAs to have a good intuition of relative impacts and what’s important to focus on. But many projects we are doing earlier effective WBLCAs in DD thru a bay model, or using EC3 or OneClick (which has some advantages over Tally but data Transparency is not one of them). But I’m a big advocate for using targeted LCA at appropriate stages - comparing structural systems and strategies in SD, looking at wall systems and cladding in DD, concrete mixes in CDs, which will get us significant savings to show if we do a WBLCA. We have a useful internal tool for wall systems - which unfortunately we can’t share since we don’t own the rights to with the internal data - to compare envelope assemblies. I will say the underlying data in Tally has been very useful to have a framework to understand this stuff. I’m now getting into fairly detailed studies of cladding systems components (curtain wall systems, external cladding support systems) where there’s a fairly good amount of EC and potential reductions I think. We are also using EC3 probably as much or more, for both specific product research, setting spec GWP limits, and developing WBishLCAs. More and more contractors have a role and I’m excited that they are increasingly excited to participate. Value proposition: we set up the model and materials, they update with quantities from various stages of estimates. It’s a lot, but we can probably do more effective focused studies in the time we would spend on a WBLCA. On Dec 22, 2023, a

Hi Patrick, Answers to your questions below: * When do you typically run a WBLCA? As soon as you have a Revit model? Later, maybe end of DD, when the Revit model is more fully developed? At the end of CDs? * This varies from project to project. For early phase design, we’ve started doing “shoe box” models, testing different structural bays to help give early guidance without doing full building models. Teams usually make the first full building model towards the end of DD when the model is fleshed out, and the spec is in the process of being developed. At this point, the model is useful for material procurement targets. If nothing else, we always model at the end of CDs – we use these for LEED credits usually, so we need a baseline and an as-designed model we can run off of. * Are you mostly using Tally for targeted studies or WBLCA for the purpose of benchmarking? * Most of these studies are wblca models, but the full building models are useful for both benchmarking and identifying material procurement targets. As mentioned above, we’re starting to do smaller studies to help guide early phase decisions without burdening the team to define too much * Do your efforts start and stop with Tally, or are you also using EC3 or Tallycat? * We work mostly with Tally (and OneClickLCA). We find EC3 to be a great tool to find better performing materials and to identify material category baselines, but it’s rare that we’ll track a full building in EC3. We haven’t had a good chance to explore TallyCAT yet. * Does the contractor typically have a role in using EC3? * Use of EC3 in our office is usually based around material select. For whole building tracking, on the projects that have chosen to track emissions through EC3, the contractor has been the one to track materials in the system. The results are always interesting to see what actual procurement values are. Hope that helps -Justin From: Patrick D

These are great questions and I have appreciated the answers posted thus far.  Here are some thoughts based on our experience with embodied carbon modeling (we don't do this for all of our projects, yet... these answers apply just to the select projects that want to dig in): 

• When do you typically run a WBLCA?  As soon as you have a Revit model?  Later, maybe end of DD, when the Revit model is more fully developed? At the end of CDs?
  • I have been trying to do a quick study using EPIC during early schematics, then more robust modeling using Tally at the end of DDs and again at the end of CDs.  I have also used EC3 towards the end of CDs, when we are writing specs, to help zero in on the products we will specify.
• Are you mostly using Tally for targeted studies or WBLCA for the purpose of benchmarking?
  • I've used it for both.  I find Tally useful to prioritize the 5-10 materials that contribute the most to that project's embodied carbon (and then use EC3 to determine thresholds we can specify around), and also have been trying to benchmark different building types across our portfolio.  
• Do your efforts start and stop with Tally, or are you also using EC3 or Tallycat?  
  • I tend to use EPIC, then Tally, then EC3 over the course of a project.  Haven't played with Tallycat yet, but hope to!
• Does the contractor typically have a role in using EC3?  
  • We have not yet engaged contractors in this way, but would love to hear how others might be doing so and any lessons learned.