A 52-year-old man attends his family physician for follow-up of elevated blood pressure noted at a work screening. In clinic, three separate visits over 2 months show non-automated office readings of 148/94, 150/96, and 146/92 mm Hg, all measured after minimal rest in a busy open waiting area. He has no target organ damage, diabetes, or chronic kidney disease. According to current Canadian guidance, what is the most appropriate next step to confirm the diagnosis of hypertension before initiating long-term pharmacologic therapy?