Installation

In Blender open Edit, Preferences, Get Extensions, then use Install from Disk and pick the greenhouse_generator zip.

Usage

1. Open the Greenhouse tab in the 3D viewport sidebar (N). With no greenhouse selected, click the big picture to pick a design and press Add Greenhouse, or open Browse by Type to see every design of a type. You can also use Shift+A, Greenhouse.
2. With a greenhouse selected, the card at the top shows its design: click the picture to switch to another design, change the seed for a new variation, and set the detail to Low, Medium or High.
3. The icon tabs hold every setting: Shape (type and size), Frame & Glass (frame material, glazing, vents, cresting, gutters), Base & Doors (knee wall, floor, doors), Interior (layout, benches, beds), Plants (theme, density, overgrowth), Ivy and Weathering (dirt, streaks, algae, condensation, wear, broken panes).
4. Weathering sliders only change the look, so they update instantly. Delete removes the greenhouse with all its parts.

Each greenhouse is a root empty with its parts as children: structure, glass, interior, plants and ivy. Plants and ivy leaves are Geometry Nodes instances; apply the modifier to make them real meshes.