Regarding design options eToolLCD has design improvement in the DNA so this is pretty well covered. There’s two options here:

  1. You can run design options and import them to seperate eToolLCD designs by changing the link between design options. Although the matching algorithms and memory do help with duplicating imports this is still a pretty painful process so see option 2 below.
  2. You can run your first option in Revit and export to eToolLCD. After matching your components (there’s some matching algorithms and memory that help with this process) you can then quickly run another option in Revit and push those changes to eToolLCD. It remembers what design you were linked to and makes those changes for you (if there’s new components you may have to match these but removed components and any quantity changes are all automatically updated). You can even build an audit trail of changes in eToolLCD to see the relative environmental performance of each option. We actually want designers to be doing this in real time, learning, iterating and making decisions on the fly.

Regarding the extraction of materials quantities from Revit, eToolLCD doesn’t actually export the materials from Revit, it exports construction components (eg Revit Family / Family Types).  The reason we opted for this was because we noticed a lot of issues with Revit files at the material level including:

  • Thicknesses (eg quantities) of adhesives, paints, finishes and hidden layers like carpet underlay or accoustic insultation etc are often excluded from Revit models. The information may be documented on the 2D plans in the Revit model but the items themselves are not modelled (so there’s no ability to pull quantities). This can be a big driver of results at time, for example intumescent paint.
  • Thicknesses of glazing are often incorrect (for a double glazed unit that is actually a 6mm : 20mm : 6mm unit it will appear in Revit as a 32mm slab. Similarly the window films are excluded from the revit file.
  • Reinforcing in concrete is rarely modelled in the Revit file.
  • The materials themselves don’t tell us how it’s installed, so we have no way of knowing what the construction impacts are from a sum of material quantities.
  • The materials themselves don’t tell us what their likely design lives are. Steel as reinforcing in a concrete pile will have a very different design life to steel used in ducting.

Take a window family in Revit that’s made up of an Aluminium Frame, Rubber, Glass, instead of pulling the individual material quantities out of Revit eToolLCD pulls out the area of the window and the user matches that with an appropriate window component in eToolLCD.  The window component in eToolLCD will have all materials and construction, maintenance, end of life scenarios etc. The advantage users get a much more accurate LCA. The accuracy of a window component doesn’t necessarily have an affect at the whole building level but if you’re comparing two different window options you want each option to be accurate for a fair comparison. So the accuracy of eToolLCD is motivated by giving design teams good feedback.

Let me know if that makes sense.