I think you can try to simulate with the mesh as is.
One way to increase the mesh quality (and size) is to add a local region refinement around the building. This should help to capture the details better and perhaps get rid of the warning messages in the process.
Of course that the best quality to capture the surface details is to use the Standard mesh. Did you give it a try already?
Hi ksalazar,
I use the convergence residuals to provide an indication of my convergence and also use the Results area on the inlet & outlet to gauge the quality of the result, see publications below.
As Simscale says… In an iterative solution where the initial estimations of variables are updated per iteration one should expect to see those variables come to a level and don’t change anymore. Result control items can be a great way to assess convergence of these variables by studying the pattern in which they stabilize as the simulation progresses.