How would houses change if we could walk on the walls?

My character has stumbled upon another planet with life, and they are able to walk on walls and ceiling, completely ignoring regular gravity (by magic, science, whatever, it doesn't matter all that much). My question is, how would the layouts of the houses change?

I'm guessing that the water appliances would be on the ground(sinks, toilets, fridge) since they are still effected by gravity normally. When these people walk on the walls, they still feel like they are standing normally (kinda like Monument Valley, I guess), so if they are on the ceiling, they feel fine. Furniture can be mounted to the walls/ceiling by hooks and extra strength fasteners, so those can be placed anywhere.

I know this is kinda vague, but I'm still figuring out what kind of rules their gravity works by. Like, if you're holding a coffee on the ceiling, does it fall ten feet to the floor or just sit in the cup normally. Lots of little details to smooth out.

Not much. We don't use walls (as floors) not because we can't walk on them. We don't use them because whatever is there interrupts what you are doing on "main surface". You ever hit your head on a shelf? Now you hit it even more because there are other things on the wall. Hit your toe on a nightstand? Now you hit your arm, shoulder, hands.

Everything on a wall casts a "shadow". That's why the most usable and space efficient are cabinets from floor to ceiling. And there wouldn't be even much change in those are humans put in the "middle" things that have a lot of use. Going down and up the use of things stored fall. Having ability to reach from ceiling would just expand the "usable zone".

Remember that putting stuff on the ceiling would mean that whole place must get higher (for example I very often hit my head on lamps in places where height impaired people live). And of course everything would need to be illuminated in a different way. Having a one light source at the ceiling is energy efficient. Any obstruction would cast a real shadow. So another lamp. Or glowing things.

In communist countries there was a thing called Pawlacz A storage for things that you don't use very often but often enough you don't store them in basement or garage.

So having a whole ceiling that could act as a storage could have some usage. Kind of like a dropped ceiling.

• I think it won't be as bad. From a certain amount of size you get double the space or more. For example, you leave the walls bare as walking space, but have a high ceiling so you can basically 2 rooms in there. With some added wall management you can have well thought out lay-out for walking and living. That is more efficient than seperate 2 rooms. – Trioxidane Aug 10 '20 at 16:04
• @Trioxidane That's a socioeconomic problem. Again, my greatgrandparents had ceiling at 190 cm not only because they were small. But mainly because having high ceiling was a waste of materials. Which they couldn't afford. and theyn you need to heat that space. This is the main reason mansions, palaces exist while half a mile further you had mud huts for peasants. – SZCZERZO KŁY Aug 11 '20 at 14:55
• @Trioxidane If the anti-gravity applies only to lifeforms, then anything stored in that furniture would fall to the floor when it was opened as well as the furniture itself unless it was nailed to the ceiling. – jastako Aug 11 '20 at 21:35
• @jastako you would need shelf with a solid "top" instead of "bottom" while allowing access to the contents. Perhaps a glass surface would do, or maybe they swivel? – John Dvorak Aug 12 '20 at 11:17

For multistory buildings, you can substitute treadmills for elevators and escalators. They will occupy less space, use less power and might even be more comfortable and faster. On top of that you can walk on them to add your speed to theirs. It would be much like the treadmills you see in modern airports, only vertical. You also don't need stairs.

Since walls and the ceiling are now usable, social space, illumination gets more varied and looking more like floor lamps.

But the biggest impact is how much useful space you have. If you consider a cubic house that is $$x$$ meters/feet long, for humans on Earth you have $$x$$ m2/ft2 for a layout - but for such creatures in their homes the same house shape would mean 6$$x$$ m2/ft2 for home modeling (floor + 4 walls + ceiling). You can fit a lot more stuff in it. You could have a living room on the floor and a home theater on the ceiling, for example.

• You also don't need stairs. I'm not so sure about that. If it's technology (ie, artificial gravity), I'm going to want a backup for when the power runs out. Magic... probably (especially if those peasants who mop the floors aren't allowed to use it). – Clockwork-Muse Aug 10 '20 at 23:39
• I don't agree that the available area for layout would increase 6x. Even in a house with very large rooms you're going to have considerable overlap at the edges where one side of the room will take up space that an adjacent side no longer can. In most houses we're familiar with this would be an extremely large overlap - in my bedroom I would be surprised if available layout space increased any more than 2x! Perhaps in this universe rooms would be much taller to compensate. – Sellyme Aug 11 '20 at 0:56
• @Renan In Europe, having less than 2.6m seems to be not uncommon, unless you live in an old house with high ceilings. Source: having lived in multiple houses and flats in more than three European countries. – Graipher Aug 11 '20 at 6:41
• If I understand the original question, then only the living aliens / beings are able to smoothly walk on walls. This means you don't really get extra "floor" space - you can't really have a bookshelf on a wall that is now aligned to the wall because it still has to respect gravity. Basically, anything on a wall / ceiling needs to be nailed down. Also, while stairs would probably be overkill, a simple ladder would suffice as backup (as noted by @Clockwork-Muse). – Shaamaan Aug 11 '20 at 7:34
• To add to @Sellyme's comment - This is a variation on what I tend to refer to as "the corner problem". To wit: when you're dealing with things placed against adjacent walls, the corner often becomes "dead" space, or otherwise inconvenient to access. Kitchen cabinets are the most readily available example for this, because they're often quite deep to provide a good work area; take a look at any cabinetry site to see how they try to get around the problem (or hide it). Then, keep in mind that cabinets are usually taller than they are wide... and the direction of gravity will be a factor. – Clockwork-Muse Aug 11 '20 at 16:30

Walking on walls doesn't make that much difference. Everything else still fall down. Shelves, cupboards and bookcases are still the same and will will take up every available vertical surface.

Along with windows. What happens when you step on one? Does it had to bear all your weight? If so, you've got lots of serious hazards. It would not be safe to talk on a surface littered with such traps.

You can stand on the ceiling, but your coffee still falls towards the ground. You have to hold your cup upside down; drinking might be difficult and messy.

It gives you slightly more space, but only slightly. People on different surfaces are still going to get in each other's way,and bump into furniture on other surfaces.

With high ceilings you could use the extra floor space for dance floors, exercise room, meeting space or anything that does not require any small objects -- because anything not velcroed down will fall to the floor. The limitations mean that it may be more like having access to an outside space (eg a flat rooftop) than additional living room as such.

Larger rooms, smaller houses

The rooms will most likely be shaped in a way that 2 sides are close enough you can walk with little danger of hitting furniture and possibly each other. The sides will be used for walking and one side might be more heavy with electricity and water, although it might be inside the side. One side might actually not be used for walking, as requiring to have a person's lenght worth of distance without furniture on every side would be wasteful. I say sides, as the box can be flipped any way you like. Further floors can be reached by how you would normally walk to your bedroom, only via a side. This makes a volume more efficient, making it possible for houses to be smaller with more stuff.

A larger box can also be used. This means 6 sides are useful. It will create a large empty space in the middle. If your box is big enough, you can add another plateau in the middle for more usable space. You can always walk there anyway, as you have at least a walkway to it.

Lighting would probably go to light strips in the corners. This way you have more equal lighting throughout the room. With the box where you mostly use 2 sides for furniture you can add a lighting rig that lights each side independently.

Heat would be just the same, only you have a warm ceiling, so in winter you would be there more often. Heat differences would be much higher, so heating might be more like floor heating, that heats the room more equally.

It may seem obvious, but a big difference would be

No stairs

In every house apart from bungalows, you need stairs to get to the next floor. Stairs occupy significant floor space and volume, because the stairs cover a similar area on both floors. Spiral stairs are sometimes used where space is very limited, but they have serious limitations (try carrying anything heavy or bulky up them!) so are not popular.

If you can walk on walls though, you don't need stairs. A "lift shaft" from the ground floor to the top floor will be perfectly adequate for people to walk up and down, saving space which can be reclaimed for rooms.

• "Spiral stairs are sometimes used where space is very limited, but they have serious limitations (try carrying anything heavy or bulky up them!) so are not popular." They're also illegal for in some places for fire safety reasons. – nick012000 Aug 11 '20 at 6:05

I think rooms would often be shaped like hexagonal prisms, like honeycombs in a beehive. A 90 degree transition seems like it would be annoying and disruptive even with magic, and it'd confuse the senses.

The transitions in a hexagon are much more manageable, enough that a person could probably run a circle around the walls like it was a giant hamster wheel. A circular room would be great for a gymnasium though, good place for a running track

You could do something more exotic like a building made up of 3D tessellating polyhedrons, but the honeycomb shape seems more practical, buildable, and would preserve the convenience of rooms having a large flat surface (well, two of them in this case)

First off, I think houses certainly wouldn't have to be as big, as space would be more efficiently managed, but you'd have to be careful where furniture is placed so you don't have to constantly dodge it while on another plane. Having vertical as well as horizontal divisions would also certainly make for some funky house shapes, and houses might be built in height more often than not.

In terms of lighting maybe a chandelier-type light that hangs smack in the center of the room (imagining a room as a cube) and casts light in all directions might be an interesting way to go about it - with just one light switch you could illuminate 4 planes/divisions.

I'm not sure how the stepping 90 degrees into a vertical plane would work, but rounded house corners might be a thing, provided you want to reduce the strain on your joints when you do it. Not sure how relevant this is though, given that they seem to defy other laws of gravity.

The Structural Integrity and Materials of Walls and Ceilings Would Require a Higher Standard

This was one of my childhood fantasies - to be able to walk around on the ceiling. Then it occurred to me, gazing up at the removable tiling and the thin plastic covers of the fluorescent lights on the ceilings at school; there was no way any of that would bear my weight. And at home, lying on the top bunk and putting my hands and feet on the spackled plaster ceilings, I could tell that they, too, wouldn't bear my whole weight - to say nothing of the havoc my shoes (or feet) would work on the spackle, or how uncomfortable it would be to walk on. And nobody is going to use sheet rock to make walls, if it's expected to bear foot traffic!

Even brick or stone or concrete walls, even sheet-metal roofs, are not designed to bear people's weight anywhere, at any angle, all across their surfaces!

The engineering questions regarding the walls in your living room would be very different if each wall was expected to have the same maximum weight tolerance as the floor. If you also want to, additionally, hang or otherwise attach pieces of heavy furniture on a wall (like a large couch, which can be nearly as heavy as a compact car), you need the wall to have materials which will bear pulling at various angles, not just "pushing" by the occupant's new definition of down.

Sure, there would be layout differences purely for convenience. I can imagine large rooms as having interesting columns or other vertical surfaces in the middle, as additional pathways to the ceiling. But setting aside any convenience questions, or different layouts... The impact on engineering and materials required to build buildings which not only keep out the elements, but bear the weight of (multiple) adult people in almost any direction on any surface...

"Timmy, this is not an expensive house. You can't have both of your friends with you up on the ceiling at the same time. Someone has to come down, or I'll make you all come down."

A lot of things you take for granted would have to change.

Not much would change about the inside of the house - as other answerers have said, objects on the ceiling are still affected by gravity, and you can't just furnish another room on the ceiling even with proper mounting because of clearance issues. Sometimes you might see slightly taller rooms intended to be used both the right way up and upside-down, but if you have the means it's much easier to just add another floor and avoid the hassle. Especially since a simple door in the ceiling/floor is enough to move between the upper and lower floors.

On the other hand, the place would need to be much better secured on the outside. Any walls or fences you build around the house will be completely ineffective in warding off intruders unless you put barbed wire or other deterrents on them. Living on a higher floor of an apartment building no longer means you're safe from someone breaking your window. The roof of your house is accessible from the outside just as easily as it is from the inside, and so on.

The model in my mind is Dracula in the film Van-Helsing (with Hugh Jackman)

Aside from general vampirism, he can stroll casually up walls and end up on the ceiling. This doesn't affect anything he's holding, even his hair follows normal gravity to some degree.

The fact that gravity still affects any objects aside from the people is a major factor.

The walls are impractical for most purposes, things will fall sideways, you can't really eat, drink or put objects down without special care.

The ceiling is much the same.
So while you might be able to sleep in a bed on the ceiling, you can't really do anything else you'd want to do day-to-day, even your wardrobe won't be convenient to use in your upside-down bedroom.

So the walls and ceiling are most useful as a route to more conventional rooms.

You might see fewer houses with stairs, but there are advantages to stairs anyway.
Imagine trying to carry a tray or box of loose objects underneath your forearms when you're on the ceiling!

Human physiology is not really well suited to carrying objects under such conditions.

I imagine houses would be built mostly conventionally, rooms stacked on rooms. But in some cases, you'd take advantage of the wall-walking to traverse up, over and around into more private areas that can only be reached by wall-walking.

Like, if you're holding a coffee on the ceiling, does it fall ten feet to the floor or just sit in the cup normally. Lots of little details to smooth out.

Sorry, but you've got more than little details to smooth out.

As soon as one way of movement can ignore some of the existing energy constraints (walking on walls ignores gravity), you have to take care, or you get perpetuum mobile, aka infinite energy, rearing its ugly head.

Make a high frame, one side of which is a slick metal wall. Take a big block of something heavy. Attach it to some railing on frame corners, so it is stable. Add some pulleys etc, and let it fall slowly to ground. That will generate you some energy in pulleys that you can easily convert to electricity. Then, instead of lifting it back, push it along the wall. Make the block be as slippery as possible to minimize friction. In fact, there are ways now, that claim to reduce friction to almost zero on macroscopic levels, but it even needn't be that bad. It is very possible to push even normal heavy loads across floor that you can't lift, showing that pushing uses way less energy than lifting.

Blam, you got energy. If energy of pushing < energy gained during fall, you get an energy surplus during fall = free energy. If you need human to push it, it might not be that bad. Otherwise you can just store that fall energy in a spring or something and make the push happen automatically. Probably will still get more energy out than you put in.

In fact, storing gravity energy is a thing, with a number of attempts currently in the world. And that is even without having the luxury of lifting the weight without gravity.

What happens in worlds with infinite energy is debateable. However, as soon as there is too much energy in something, it tends to explode. There are several questions here on WB about that.

As an afterthought, if people can walk on vertical surfaces, you gotta redesign security. Upper floor windows are now not safer than 1st floor. Mountain ranges are strolls in the park. What about cars? Do cars with peoiple in them can drive on walls too? There are tons of questions and on almost every aspect the world is very weird indeed.

• I don't think that scheme would work - though a similar scheme involving a person with a rope harness hooked up to a pulley that walks up the wall, and then jumps off to turn a generator should work. – nick012000 Aug 11 '20 at 12:22
• @nick012000 why wouldn't the scheme work? nothing in op says it shouldn't – Gnudiff Aug 11 '20 at 13:40
• Because normal furniture is still affected by gravity normally, since it needs to be fastened to the wall. – nick012000 Aug 11 '20 at 14:09
• @nick012000 ah yes you're right. need to replace block with a human or a bunch of them. – Gnudiff Aug 11 '20 at 14:47
• This could be simplified down to a giant turbine where people stand/sitting on the outside edge of the blades. Their weight pushes the blades down relative to themselves so they are constantly pushing the blades in the correct direction to cause the turbine to slowly turn. The turbine is then directly hooked into a generator and thus power. – Anketam Aug 11 '20 at 19:07

I'd say houses would be a lot smaller. With 4 walls, every surface can be used, instead of just the floor. I'd also say that every room would be divided into 8 cubical rooms, one in each corner, with one corridor in the each of the x-y-z axes. Doors would be odd; I'd expect each would be a trapdoor that opens either way, with latches holding the trapdoors open. I would also say that the main entrance would be at floor level, since the surface of the planet is the same, and that the floor would store small objects that are susceptible to gravity. Heavy objects would be placed on the floor due to the danger of them falling. Ceiling fans would be banned due to their safety hazard. There may also be "pull-up bars" that you'd jump to, grab, and then use to swing yourself to the ceiling without having to walk to and up a wall. Finally, I'd say that ceilings and walls would have to be stronger due to the constant strain of people walking on them.

Bonus cup design: A closed cylinder with a spout, facing away from the drinker's face, at the top. Pushing a button opens the spout, and you pour the drink from the spout onto the roof of your mouth.

How would houses change if we could walk on the walls?

You would have to have carpets or lino everywhere. You can't leave foot marks all over emulsion paint.

Toddlers would be a pain. They could stick their fingers into light fittings mounted on the "ceiling".

Windows would be a hazard. If you tread on the glass and break it (or don't notice the window is open) do you fall out of the window or does gravity work differently on the inside and outside of the building?

Mains sockets will be worse than they are now because where do you put them? Several on every wall, floor and ceiling?

Don't open the velcroed-to-the-ceiling fridge without thinking or the contents will fall on you.

Pets would have great fun running around the walls until they jumped. Then gravity would suddenly come from an apparently different direction and splat them on the floor.

Designing a squash court would be a challenge. What happens if you or the ball cross a gravity boundary in the middle of the room?

Vacuum cleaning?

Very tall and wide rooms to avoid heads clashing in the middle?

Heads would clash on surfaces at right-angles to each other.

Which way up would the TV be so everyone could watch?

It depends on the constraints. If you have loads of space to build then with a large sprawling house with plenty of floor-space, walking on the walls doesn't add a huge amount of valuable space; in fact you lose space because you need to leave space around the outside of the room to access the wall.

If, however, you have limited building land, then houses could be built vertically with a very small footprint; say you want a house with 4 16ft x 24ft rooms, with a ceiling height of 9ft, you could build that on a 16ft x 9ft parcel of land, whereas in our mundane world you would need at least 32 x 48.