grayfields

Could be any number of reasons (including folks getting into a job over their head/finances), but typically the initial general labor activities (demo., framing, drywall, etc...) are the most efficient tasks on the job. As you get into more detailed finish and skilled trades work, the availability of materials/labor, avoiding stacking workers in the same space, sequencing requirements that narrow the critical path, inspections, and design revisions/change orders slows productivity, increases durations and creates lag. Then, likely some event (approvals, showing, sale, LD milestone, etc...) causes a mad dash to completion.