Just as an aside, my retired Navy pal calls the shower "the rain room."
Does anyone recall or even use the word REFECTORY any more? In my boarding school the refectory was the large room with multiple tables where we gathered for meals.
In New England the phrase "Great Room" is coming to mean that the house has a huge living room ... sometimes it is a live/dine room. The phrase is becoming an Up-Market catch phrase and real estate agents and Realtors are becoming very fond of it, even when it's not particularly applicable.
Now, about "yards" and "gardens" and the differences in definition by US and UK users.
Around here when someone says we are in the yard they mean somewhere on the land around the house that is owned by the home-owner. The garden is the part with flowers or blossoming trees or any area set aside for repose and not just a swath of grass.
Patio -- cement pad or flagstoned area, uncovered, near the back door generally with chairs for sitting.
Porch - integral part of house construction and attatched thereto ... sometimes ornate ... can be large sweep across front or back of house. It can be modest in size but to qualify as a porch it must have room for a few chairs and table for sitting and watching the world go by on warm summer evenings.
I have gone on long enough.
wow