By checking the warm-up's “before you move on” conditions and then transitioning deliberately. The warm-up doesn't fade out — it hands off. When the talk has stayed about them, the hot topic is found, and the room is easy, you name the turn into the work: that's a transition, and transitions are one of the documented ways you control an appointment without controlling the homeowner.
The short answer
The checklist-before-moving-on exists because reps leave the warm-up in both wrong ways: too early, because small talk feels unproductive, and too late, because it's comfortable. The check makes the exit a judgment instead of a mood. Conversation about them — check. Hot topic found — check. Positive, unforced room — check. Now the warm-up has done its whole job, and continuing it spends the appointment's energy on the part that doesn't decide anything.
How it runs
Control in this system runs through transitions: you use their answers to earn the next step, and you say the turn out loud so the homeowner comes with you. Out of the warm-up, the turn sounds like moving from their world to their problem — from how long they've been in the home to what made them start looking into the project. That question is discovery's opener, and it lands because the warm-up built the room it lands in.
What you never do is apologize for the turn (“well, let's get down to business”) — it frames everything before it as wasted time and everything after it as a pitch. The warm-up was the appointment, beginning properly.
Spar trains the documented sequence, step by step, and grades what you actually ran. Round 1 is free. Spar before you knock.