I have had that dream several times. Used to fall asleep watching America’s Castles on Sunday morning which I attributed the dreams.
I looked it up once, I think it meant something new and good in your life.
I get this too - the “problem finding a private place to go to the bathroom” part.
And yeah I’m always finding new rooms in my dreams. Not usually full of treasure or antiques. A lot like Tethered Kite - just more rooms in my house that I’ll never get around to taking care of.
Lots of times in the dreams I have a ton of people over and they are spilling in to these new rooms.
I never once had a dream like this until I bought my house in 2005. I have them weekly or monthly since then.
Not often, but I have had several dreams where the layout of familiar building would be mixed up or changed around, often with extra or previously undiscovered areas/rooms. Generally they have been in familiar buildings or homes I was living in.
I actually found one, sorta. I used to live in and “manage” an old 1908 or so apartment Building in Downtown San Jose. There was a back stairwell, we didnt use much, not safe. Painted over, halfway down on the landing was a large closet/storeroom.
I have this dream all the time. When I was younger, I had it so often that I wondered if there was some pathological issue at the root of it. My mother reassured me that she, too, had often had that dream, and I just chalked it up to my family weirdness.
For the last decade or so, there has been a new feature: The Dream occurs in a house I have just bought, and the discovered/secret room is full of neat stuff that I can sell on eBay.
I like to think that the dream in general my brain is reminding me that I am surrounded by resources/opportunities, if I would just keep myself open to them.
I have many times had variations of this type dream. Usually one of the house I have lived in, or schools I went to, are laid out basically the same as reality, but there will be some small differences, like an open doorway where there wasn’t one, or the furniture layout different. The consistent thing about them all is that the differences are always there and the same in every dream, even though they happened over a period of years.
Many of the streets and roads I traveled on a lot are slightly different in some way, but always have the same differences every time I travel them.
One fairly common sequence is that I am running from someone,or want to get to some other place in a building, and I walk up to a wall and find some feature about it (light switch, spot, paint mark, etc), push it, and an elevator door opens up right in front of me in a blank wall. I get on the elevator, the doors close, and it takes me where ever I am wanting to go. Very convenient.
Another vote for “all the time”. It’s always that feeling of “why the heck did I never notice this before?” that’s the oddest part.
I have dreams like this often, too. Mine have all the same features you name, Zipper. To the last detail. That makes it seem to me like these specific details have their own meanings.
Nope, never had that dream. Not that I can remember anyway.
Going through one of the hall lockers in my high school and finding a hidden indoor pool that was about the size of the entire school building.
Actually had that dream three or four times…
I’m sure I’ve had that dream at least once.
I actually have lived in a house that had extra rooms and corridors. The house was built in the very early 20th century and the father of one of the previous occupants used at least one of those extra rooms to make wine during Prohibition. (When we lived there, my parents tore out a wall and found the still-full bottles wrapped in Saturday Evening Posts from the 1920s. We had an article in the neighborhood newspaper and everything. They replaced most of the bottles but kept a few.) Us kids weren’t allowed to go exploring because some of those secret rooms might have been unsafe.
It was kinda cool living there, though. There were dumbwaiters. 
Me too, many times!
There was a house (I don’t, of course, remember exactly which one, we moved a lot as kids) that had a closet and if you pushed all the coats and stuff out of the way on the far left and climbed UP, there was a place to put your feet and it kept going and you emerged on a secret floor. Very dusty, forgotten, abandoned, oddly elegant.
That one’s only in dreams.
I’ve had two in real life: in High School there really was a closet with a trap door that opened to a short flight of wooden stairs that went down into the crawl space below the no-basement house.
And in the homeless shelter I lived in in 1984, which was an otherwise not-in-use building on Creedmoor Psych Hospital grounds, there was a massive double door chained closed in the basement down some stairs we weren’t supposed to go down in the first place, and one day a friend and I climbed up, stood on the chains after pulling the door out to max extension and slipped through and onto the other side. Fallout shelter, massive array of interconnected hallways with abandoned rooms. Ancient moldy patient charts. Glass barreled syringes. Silver nitrate ampules in the dentist’s office that I took with me for cold sores. Boxes marked with 
, canned food and medical supplies and blankets and whatnot. And the far ends of the tunnels went under still-in-use psychiatric ward buildings, we could hear people upstairs from the chained-on-the-other-side doors.
I used to be a security guard in a large school administration building, with a complex series of rooms and corridors. I was there for eight years so I got to know the place pretty well, even navigating when the lights (except for running lights) were out.
I often have dreams in which our home–we actually live in a double-wide mobile home–conforms to the dimensions and size of that building, and the setting is often shortly before my Mom and stepfather (who actually split up more than 40 years ago) are sleeping and I worry that I’ll make noise and wake them up.
I had a dream where mrAru and I had just bought back 2 properties previously owned by my family, my grandparents summer house and our original winter house [we had a summer house we moved into after school let out for the summer and moved back into just after labor day and school restarted] and I was going through the winter house deciding who was going to have which bedroom, and the walk in closet had a secret room behind it which was only in my dreams, that lead into a more elaborate and hugely larger unfinished attic, which also doesn’t exist. That attic would be so freaking great if it were finished off and turned into a large recreational space! I could so see adding skylights to get some natural light into the attic, and there would be 4 or 5 great nooks for computer areas.
Ah well. Last time I had a dream like that, it was the basement that had all the extra space. At least that is plausible.
I have dreams like that a lot–finding someplace to relieve myself. There were five pairs of restrooms in the building where I worked; half of the fourteen places I remember us living in, out here in California, had two bathrooms.
And usually I woke up shortly after that needing to answer nature’s call.