Expanding Fronts is a massive modification for Star Wars Galactic Battlegrounds aimed to breathe life back into the classic LucasArts strategy game by adding various new units, features, and gameplay elements. Each of the 8 civilizations are being reworked and enhanced to make each feel more unique and authentic to the universe, while maintaining the classic Battlegrounds gameplay. In addition, the Scenario Editor is being filled with hundreds of new units, buildings, effects, triggers, and objects to allow campaign and scenario designers more freedom than ever before.
In the films and various EU sources, it's shown that the Wookiees generally construct their buildings among the treetops of Kashyyyk. For the sake of consistency with the other civilizations in GB, the stock Wookiee buildings are decidedly grounded. Here are a handful of new 'elevated' Kashyyyk structures, courtesy of SWGBH user Wellst
Whether or not these buildings will serve a function outside of aesthetics is undetermined at this point; but you're free to suggest a use for them.