When: May 21-23, 2024 Where: Retrotec Headquarters. 1060 E Pole Rd, Everson WA 98225 Cost: $1650 per person. Pricebreak for 3 or more attendees (call for more info). Expand your skillset with Retrotec’s 3 Day Large Building Training! This intermediate course will provide an understanding of the role that air leakage plays in buildings. The principles in this training course apply to residential houses, apartment buildings, office, commercial, high-rise, and industrial buildings, as well as an array of other applications.