I want to make some templates and I was wondering how one makes a building template without gathering all the materials to do so in normal mode
You can create and save without actually engaging in the build!
use debug tools to stamp in the talismans for the crafter jobs, then level up the crafter using shift+click on them and picking Level Up. once you have the crafters at level 6 enter build mode and you have full range to all the items. Build and design to your hearts desire!
Even simpler: select a hearthling, hit Ctrl+C, and type
promote_to blacksmith or whatever and then shift-click and level them up to max. You still might need to use the item stamper to stamp special items that are only otherwise attainable through trade or town progression.