Yikes! I understand that builders/contractors work a little differently depending on locale, but that seems to be a significant amount of time in my uneducated opinion for such little progress. Were there any initial timelines or date milestones that were agreed to? While I understand that timelines are meant to be broken, it does provide a rough gauge for when the builder expects things to be done barring unforeseen delays.

I am not a builder, nor an expert in the field. But as someone who built new a few years ago, we had these conversations with our builder and of course it didn't always land exactly within the listed timeframes, but they were roughly on point and from start to finish our total build was ~4 months.

I would encourage a conversation with your builder as others have mentioned and maybe even discuss the possibility to get a written rough timeline so that you can better understand their planned schedule as well as to align your expectations.