Believe it or not, my studies are in architecture, I even did a master in structural analysis that I didnt use much (it helps to understand how a building will blow up, XD), and studies in solar energy. So more than 10 years ago, when I started with the 3d world, my first renders was about architecture. I worked with multiple studios and agencies creating images to sell houses. Keep in mind this is quite old stuff (between 2002 – 2007), and I lost most of my work. Here also an old album

As an extra, I have an old old site, started 15 years ago, where I keep some of my first renders in 3d, and also I shared some excel spreadsheets to help calculate multiple structural analysis problems:
https://sites.google.com/site/eloiandaluz/calcul-estructural/aplicacions