In designing a tiny, moveable, totally-off-grid house, I think it's important to really understand what 'home' means. Specifically where, to you, the line is between 'camping' and 'home'.
If you are planning on sharing the space, there needs to be a consensus. Some people go 'camping' in a cabin with showers, televisions, refrigerators, sound systems, and all sorts of gadgets. Some people aren't 'camping' unless you hiked everything in on your back and there are no other people for miles. Some people are at 'home' in a tent, or a van.
The Partner and I have talked a little about where the line is for us. If we're building a tiny house to live in, we won't be happy if we feel like we're permanently camping. These are some of the things we decided were necessary to make a theoretical tiny house into our home, approximately in order of how easy it is to describe what I mean.
I get cold very easily. If I'm putting on thermals, a two sweaters, and a wool hat to get up in the morning... it's not home. If it isn't easy to keep the temperature at least 65* during the day, and above 50* at night, then I can't live there. A tiny house needs to have an easy, effective heating system.
Conversely, If it's over 95* in the house at ten at night and we're laying on the bed with all the blankets off sweating and trying to sleep, we suffer, the Partner more than me. With a small house, with windows open, this shouldn't be a problem in most climates, especially if it is shaded during the afternoon.
I touched on this above, but it gets broader. If it's too loud at night, or there are too many outside lights, we cannot sleep. If the bed is too small (smaller than double/full), we cannot sleep. If the mattress is lumpy or uneven or too thin, I especially cannot sleep. If the ceiling is too close to my face, then I definitely can't sleep, because I know in some small part of my brain that I will suffocate. (Yay for claustrophobia!) Part of this is dependent on where you situate the tiny house, but part of it is design. It should be moderately soundproof, and have the sleeping area comfortable, airy, and with a good mattress (no futons!).
Cooking is a big deal for me. I cook everything from scratch. I do not believe in pre-packaged foods. If I cannot cook, then it cannot be home. That said, I don't need much to do my cooking with. I can be very adaptable. The minimally adequate kitchen for me would have a galley stove, a dorm-sized fridge, a few feet of counter space, a sink, and lots of cabinets. It's pretty bare bones, but I have found that almost every kitchen is inadequate in one way or another, but after I've cooked in them for a few months I hardly notice. This would be no different.
It would also be good to have a table to eat the food at, family-meal style.
A home has to be a place where you can relax. The Partner and I are pretty quiet, we like to have a comfortable space to read, play board games, cuddle, and occasionally have a friend or two over. This space is ideally separate from the bed. A small couch-like area would be perfect... but if due to space constraints it had to be somehow combined with the table area, we could adapt.
We have a dog. He lives with us. He doesn't need much, just a clear piece of floor for his blanket and food and water dishes, and also enough space so it is possible for him to not be underneath our feet at least some of the time. He likes to be outside, but when the weather's bad, he would be inside a lot.
This is a tricky one. How long can we be ok using a little camp shower or a dr bronner's style sponge bath? (I'm not the only one who's ever read the bottle, right?) Would this feel more like camping than we are comfortable with? On the other hand, we definitely wouldn't want to have rv style water tanks and utility hookups and all that extra weight and garbage. If we go for some sort of intermediate, it brings up the question of greywater disposal.
Also, while I am comfortable with the idea of the simplest kind of composting toilet, and I'm sure it could be designed carefully into the house, it also brings up a lot of questions about disposal. I will (maybe) write another post about those issues another time.
There are some things we wouldn't want to leave behind, that we feel strongly and positively affect our quality of life, that unfortunately eat electricity. There are not a lot of these things, fortunately.
Cellphones. We use them to talk to people. They are useful, because you don't have to go through the hassle of a land line and new number every time you move, and can be used at any time. We have lived places without cellphone reception, and it's a huge pain. I could conceivably leave my phone off all the time and just check my messages and talk to my mother once or twice a week, but then I would be completely cut off if there was a family emergency, or if the Partner was just calling to say he would be home late. Also, if one of use had a job (that being the ideal situation), they would need to be able to communicate with their work. Cellphones are a necessity to our modern lives.
Laptops. These are slightly harder to justify than cellphones, but we do use them all the time. They can play movies, music, and games, providing endless hours of entertainment. They can be used to write, edit images, and keep track of anything under the sun. Even without internet they are useful.
How do we keep these electronic gadgets fed without being hooked up to the grid or buying an expensive solar array? Apparently there are solar charger/batteries that are strong enough to power laptops. It might be worth our time to invest in one of these, as well as upgrading our laptops for more energy efficient models.
Ok, that's what I've got for today. It got a bit... less concise at the end there, and I'm sure I've missed at least one important thing, but that's what I personally think I need in a tiny house to make it feel like home. Everyone's list will be different. What's yours?