The Design Firm is a transportation related production building added during an update on... The Design Firm is a transportation related production building added during an update on 02.21.2014 as part of the timed quest called Bus Service. A total of 190 assets are needed to complete construction of the Design Firm. This is equivalent to 250 if one were to buy every asset instead of waiting to receive them from neighbors. Due to the removal of , the engineer rewards have changed.