As a building design technician you plan how heating, ventilation and cooling, electrical power, water, and drainage systems all operate in a building. You need to consider comfort and control, safety and security, efficiency and sustainability, and access, to make it easy for systems to be fixed and maintained.
When you imagine a building being constructed, you probably think about its exterior and maybe the shapes of the rooms inside. But there is much more to a building than simply its bricks and mortar.