These are the builds at the top of the size scale: 1,500 to 2,000 structures, which is the ceiling this library accepts in a single file. A behemoth Tek base, a Viking lodge, a full castle.
At this scale the resource cost is the decision, not the layout. A 2,000-piece metal or Tek build represents days of farming, so read the resource breakdown on the template page before you commit a wipe cycle to it.
Server structure limits also bind hard here. On capped servers a mega build will occupy a tile on its own, and several of these are shipped as multi-part packs precisely so you can place them in stages.

Large functional workshop base with an integrated greenhouse and mixed stone, wood and metal construction.

A maximum-scale Tek base designed around a Behemoth footprint with extensive defensive and utility space.

A three-part Gacha farm pack containing the main farm, a compact cubby section and a center support pillar.

A decorative three-build pack with two gazebo variants and a standalone treehouse design.

A large Japanese-inspired castle with multiple tiers, detailed rooflines and substantial interior space.

Two complete variants of a large Viking-inspired lodge with extensive interior and exterior building detail.

A large functional headquarters supplied with a separate twelve-foundation part for aligning a lowered storage floor.

A large residential compound focused on detailed living areas, layered rooms and a polished PvE presentation.

A large seasonal 13-by-13 defensive base layout with extensive structure coverage and fortified utility space.
2,000 structures per file. That is enforced at upload by validation, so no template here exceeds it, and packs split larger projects across separate files.
If it ships as a pack, yes — each part is a separate file you place independently. Single-file builds place in one operation and need the full material cost available at once.
It depends entirely on the material tier. Every template page lists the full resource breakdown, which is the number to check before starting the farming run.
Very likely on official and capped unofficial servers. Check your server's per-tile limit against the structure count on the card before importing.
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