Sefaira starts with one concept. You can change input and see the results change, in both the Results Grid and the Output tabs on the right of the page. 

What if you want to compare, side by side, different setups of the geometry, envelope inputs, HVAC systems, etc or some combination of all of these? Use the CLONE button to copy and paste the current setup allowing you to make a change and see the % difference between two strategies.

In this example, we set up the project as close to a starting or baseline point as we can, then we CLONE to look at the effect of, first, envelope changes and then system changes.