"Average" cost of conducting an LCA

We spend between 8 and 16 hours doing a Tally LCA on a project. That’s for one report at a project milestone. We try to do one at each major milestone- SD, DD, CD. A few notes and qualifiers: * It’s an “architect’s LCA” meaning we’re inputting the best info we have, but the person doing it is not specially trained or certified to perform LCAs * That time amount gives us the snapshot LCA- where the project is at. If we want to run comparisons of different options and use Tally to help inform some decisions, that takes more time and is highly variable. * The time assumes we have a good clean Revit model that follows office standards, with consistent naming of families and materials, and little cleanup required. Messy models take longer. * It takes longer to set up the SD phase Tally- that’s the 16-hour part. Once most of the materials are assigned in Tally, the subsequent LCAs are much faster, as they are just updates. We are now building Tally information into our Revit templates to make the process even faster. One other part that has slowed us down is that we go through our copy of the structural model and assign materials. When we get updated models, however, we have to reassign all the materials. We’re now trying to get our structural engineers to input the Tally info into their models so it remains through subsequent updates. * Includes formatting the information into a report for the team. * There was a learning curve; the first couple of LCAs with Tally took about 40 hours. Kristian Kicinski AIA, LEED BD+C Associate Principal / Director of Sustainability (he,him,his) Bassetti Architects o 206 340 9500 / d 206 536 1370 www.bassettiarch.com Need to send me files? Click here. From: Andrée Iffr

Our experience is similar to what Kristian has described. We run a WBLCA in Tally on almost all projects, and it can take from 8 hours (small project or re-run at a later phase after the initial model is set up) up to 40 hours (large project, complicated phasing with new and existing elements to distinguish, training a new team member in Tally, etc.). Of course, creating a baseline model for LEED or other reporting can up to double the amount of time spent by phase. We also run small LCA "vignettes" to study specific decisions around a material or assembly, which vary greatly but typically take 2-8 hours. We have also found that having someone who knows the project well and is familiar with the BIM model, drawings, specifications, and design decisions substantially improves the efficiency of the process. We have only a couple of people who I would consider very experienced in LCA, but many staff who are learning Tally. It seems to work best for us to have a project team member do the bulk of the Tally work with the guidance of an LCA "expert" to balance knowledge of LCA and quality of results with knowledge of the project.

I concur with Kristian’s analysis. We also do LCA at major milestones (or at least annually at 2030 reporting time) using Tally. For a well set up model it can be 3-4 hours. Average about 8 hours. Also worked through the learning curve and now have our Revit standards updated for typically assemblies and materials already built in. Jon Hall AIA, LEED AP BD+C & Homes (he/him) O +1 206.467.5828 D +1 206.902.5508 C +1 206.551.7340 F

I'll take my crack at this; I've appreciated others responses. We've been using Tally for our WBLCA efforts, and with our projects tending to run on the more complex end of things, found it could take up to 80 hours to complete a full building analysis, in line with the LEED MRc1 credit (which was the prompt for many of our clients and projects to undertake). MRc1 was our gateway drug to doing more targeted (and less WB) analyses, and we've found ways to do more limited bay or single apartment models that still capture the essential insights, in ¼ of the time. But the experience, to me, has also illuminated that the issues haven't really changed: concrete, and structure is general is the largest; envelope and interior partitions will also be significant. A goodly portion of the LCA benefit is calibrating our intuition, so we can take these lessons learned to other projects, so we can tackle those issues without necessarily doing a WBLCA. At the same time, we've been piloting LCAs through EC3, and we're getting more optimistic on the idea of better Revit standards/protocols and direct export to this platform to save significant time (there's still issues with detaching models meaning a separation from the design flow, however). There's challenges here, but optimistic it'll get easier.

Re: concrete and steel: IMO if you are not talking with your structural engineers about https://se2050.org/ , you should be. (We are just starting to.) First baby steps might be https://se2050.org/ecom-tool/ if they've never considered this before. "Want to quickly find the embodied carbon order of magnitude of your project or framing scheme?  Use this very simple estimator below that we call ECOM. ECOM stands for (E)mbodied (C)arbon (O)rder of (M)agnitude and is a basic embodied carbon estimator. ECOM allows users to determine approximate estimates of embodied carbon for a material product, an assembly of framing for comparison purposes, or even an entire structural frame. The underlying data has been gathered from publicly available industry-wide Environmental Product Declarations (EPD’s) that are applicable to North America."