One Click LCA and BIM tools


For those of you working with Tally, ec3 and #One_Click_LCA, how do you evaluate these tools?

1- Which one is more user-friendly?
2- Which one works with Revit more seamlessly?

I appreciate any insight or experience sharing.

Hi Medhiz.
I have used Tally a bit, though my primary function is a structural tech. Tally is great for early decisions once a model has been started. It works well with Revit and can quickly compare Design Options. The drawback I find most restricting is you have to convince your Revit users to be much more accurate while modeling, especially regarding material designations. That’s overall a good thing but human nature being what it is and retraining being expensive, well, you see the issue.
Tally (TallyCat)does work well with EC3.

We have a dedicated Sustainability Expert who focuses on One-Click and she reports that many of the Tally issues can be avoided with One-Click since materials can be corrected outside of the model. One-Click also works better prior to any modeling and works well with early design software and EC3.


Hello Patrick,
I appreciate your comment. Yes, modellers need to be more specific. I believe the modellers are capable of building the proper model if someone asks them to do it with the expected accuracy.
As an architect and academic, I am not comfortable changing the process after it is in the LCA software.
Thank you!

Good morning,

Thank you for the reply.

I also believe that modelers can be persuaded to model more accurately but many “modelers” are primarily designers and are necessarily more concerned with design than with accurate modeling, especially in the fast-paced world we have created for ourselves, with long procurement times, and profits nipping at our heels.

A technician, who is primarily concerned with accuracy and does not engage with “design”, as opposed to modeling, can certainly take time to be more accurate. However, there are very few technicians that I know of in architectural design practice, and the work is carried out by younger architects, whose emphasis is design, not modeling. In our firm, the other disciplines have a different mix. Out structural department primarily uses techs, though that is currently changing as more engineers leave school with Revit experience.

As a Tally user, I see many projects that purposely use Generic Models (in walls for instance) and then use Drafting Views to communicate the actual design, thus losing the ability for accurate take-offs. I know this is done for practical reasons, but it does present issues for LCA accuracy.

I believe the continued emphasis on pursuing growth at all costs, a neoliberal economic model, prohibits true sustainable design for the simple reason that profit will always outweigh people and profit. Yes, lip service is paid but the system demands growth at the expense of realizing the full potential of accurate modeling.



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Just as an FYI, you can use generic walls and then apply accessory materials in Tally to get reasonable results.

I’d caution against over detailing these models - almost everyone I know starts off trying to model everything as accurately as possible in the model, and in the end, the numbers fall off pretty quickly after the top ten impacts (in this case, I’m talking about a typical tally model - structure, enclosure, etc). you want to get the big things into the model, but not sweat the small stuff, especially given the data right now. There are large uncertainty bands in the LCA data that aren’t always immediately apparent in Tally (and EPD) reports. Tally will give you a number to the 8th decimal point, but that number isn’t tied to reality. We look at the reports through orders of magnitude. Use it as a guide to find out the whales, and focus on them.

If we hit a point where we’ve taken care of all those top materials, then we can focus on modeling the small things.


Our internal workflow uses both Tally and One Click. For ‘design models’ which lack detail (generic walls, model-in-place components, etc.), we’ll use Tally to do an early LCA or (hot take here) import the BoM generated in Tally to OneClick where we can test effects of procurement decisions. For the final analysis, we use OneClick.

We’ve found Tally’s Revit plug-in much easier to use than OneClick’s version, but I hear OneClick is working to improve the usability here.

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Very insightful. Thank you!

Hello Jack,
I appreciate your thought-sharing in this area. Do you use BIM export to One Click or do you use Excel to upload the data to One Click?