Installations that aren't useful to you anymore can be demolished. Demolishing an Alchemical Aaltar, Haarvester, Reservoir, or Maaker burns the underlying NFT and returns 50% of the Alchemica invested into it, including upgrades.
Decorations, however, can be freely equipped and unequipped without burning the NFT.
Demolishing cannot be undone once confirmed onchain, so be very careful!
Important note: AavegotchiDAO will be voting soon to potentially remove the 50% Refund, so do not include this refund in your calculations until that vote has finished.