Placing House Add-On's, by Levi and Candy
Introduction Tailoring Add-Ons: Loom | Spinning Wheel | Small Bed | Large Bed | Pickpocket's Dip | Training Dummy   Smithing Add-Ons: Anvil | Small Forge | Large Forge   Tinkering Add-Ons: Stone Oven | Flour Mill   Magery Add-Ons: Stone Altar (Abattoir) | Red Pentagram

Stone Oven Facing East
Size of object: 1 tile x 2 tiles
Direction object extends from targeted tile: South
Notes and personal observations:

Had to switch houses on this one because Candies upstairs was a bit messy.
Ovens, Mills and Fireplaces (if they ever become craftable) have to be on the top story of any structure.

Stone Oven Facing South
Size of object: 1 tile x 2 tiles
Direction object extends from targeted tile: West
Notes and personal observations:

Had to switch houses on this one because Candies upstairs was a bit messy.
Notice that the oven extends West, not East from the target. How strange.
Ovens, Mills and Fireplaces (if they ever become craftable) have to be on the top story of any structure.