FARMINGTON, MICH. — Colliers International has brokered the sale of the Professional Pavilion in Farmington, a northern suburb of Detroit. The sales price was not disclosed. The 21,338-square-foot medical office building is located at 23133 Orchard Lake Road. The buyer, Healthcare Real Estate Services LLC, plans to do interior and exterior upgrades, including repaving the parking lot, lobby renovations and new landscaping plans. The company also plans to add an additional 14,600-square-foot building along the same road. Two tenants at the property include Beaumont Pediatrics and South Oakland Gastroenterology Associates. Gary Grochowski and Bryan Barnas of Colliers represented both the buyer and the seller, Ziegler-Michigan 5 LLC.