Upgrade the Carpenter's Shop first, then the blueprints
Data from build 25583279, updated
The Carpenter won't sell a greenhouse blueprint until Upgrade the Carpenter's Shop is finished. That is a Donation Box project, and it is the first thing to save for.
After that, each greenhouse is a blueprint purchase plus a pile of building materials.
Next Town Upgrade starts Upgrade the Carpenter's Shop. It arrives once you meet this condition: Town rank 70; Completed Upgrade the Saturday Market at least 1 day ago.
Letter: Next Town Upgrade from Adeline
Upgrade the Carpenter's Shop takes 100 Glass, 100 Refined Stone, 30 Crystal and 30 Obsidian. You get 50 renown and Small Greenhouse White Blueprint back.
The quest reward covers the White blueprint, so skip the 50,000t unless you want another colourway. Bring 20 Refined Stone, 20 Glass and 20 Hard Wood to the site. It covers 6 by 3 tiles.
Small Greenhouse · blueprint 50,000t at Carpenter's Shop · White, Wood
Shop gate
Buy the blueprint at Carpenter's Shop for 100,000t, then bring 40 Refined Stone, 40 Glass and 40 Hard Wood to the site. It covers 7 by 4 tiles.
Large Greenhouse · blueprint 100,000t at Carpenter's Shop · White, Wood
Shop gate