Single Fam Vs Commercial New Construction Timeframe

[Danny N.]

Just Curious, maybe the more experienced investors can shed some light on this : Why does residential, single family new construction take ages to come to fruition while commercial moves quick?

 Or is it something that happens in my area ( Massachusetts) ?  I see new construction spec builders take months to move from one stage to the next while commercial buildings are framed and roofed sometimes in days. why the disparity?