Hidden dog crate - no DIY instructions as this is for sale but can totally DIY this for less! If I ever got another dog I am so doing this, no crate in house, no dog bed spread over the floor and I'd have space to display :D
Turn a second-hand dresser into a pet bed and treat station with a few coats of paint and some Milk-Bone jars. A side table turned upside down or an oversize drawer with a large floor pillow will also double as a shabby chic dog bed when painted.
"Dog house" is actually hidden access to a doggie door, providing visual & physical security against intruders. Always thought it would be cool to have a dog door into the garage on the side of the house with a covered dog run.