February is when the office is thinnest and the buyer is furthest along
Pools get decided in the cold months, which is exactly when most builders staff the phone as if nothing is happening.
Off season inquiries are frequently the most valuable of the year. Somebody researching in January is planning, not browsing, and they are usually talking to two or three firms in the same week.
Answer speed decides more of these than the pitch does. A call returned the same hour lands in a very different conversation than one returned in two days, by which point another builder has booked the yard visit.
Set a rule and staff to it. Who answers, in what window, and what happens to a form submission that arrives at nine at night. Route to a mobile phone if that is what it takes.
Then check reality. Pull your call logs for the last off season and count how many rang out. It is the cheapest research available and it is usually uncomfortable.