You can still control the temperature in a Passivhaus, the difference is just that you need much less energy to heat it.

It won't solve the problem that people prefer different temperatures, though.

> about what a comfortable temperature is ... it seems like unless she can actually "feel the heat" as it were, she is not comfortable

You wrote it yourself... Comfort is not with the temperature (scalar quantity for C implemented roleplaying¹), it is with the "warmth", with the effect obtained in the internal environment, a quality you feel. This is why heat exchange feels ineffective compared to radiators. Sheer temperature is only partially indicative even outdoors.

Spend time in a car under the sun, in general, but even when paradoxically heated by the sun to a good internal temperature in cold winter, and see the reaction of the body.

(¹A memory cell with a scalar for "health", one for "strength", one for "agility"...)

To feel warm, radiation is more effective than temperature.

And it has to be the right radiation (hence the example of the (bad) environmental quality of a car under full sun).

Sounds like one of you might have a health condition. She could be underweight or anemic, you could be overweight or etc.

I'm pretty sure that totally healthy people also prefer different temperatures.

And it's common that women prefer it slightly warmer; men do have a slightly higher metabolic rate on average even when they have the same height/weight, and those extra calories that the body uses end up as heat.

It's common, but I find it strange considering women have overal much more fat, so you would expect the roles will be reversed.

Maybe not a health condition, might just be the body's set point.

There are three biological states: body is cold and needs to warm itself, body temp is right (no effort required), body is hot and needs to cool itself.

I was born in hot southern climate, my wife in a cold norther climate. For me, "body is cold" is rather unnatural and uncomfortable. For my wife, "body is hot" is the same. Her internal furnace is always on, my internal cooling system is always on.

She is happiest at 18C ambient, I am happiest at 22C.

If you want a biological mechanism to explain this, it's called epigenetics, and the key factor would be the environment your mother was in while you were in the womb and she was forming your body.

I'm not 100% sure of this. Totally anecdotal but... I was born and raised in a continental climate, where during winters most day you would stay between -2C and 1C and sometimes you can get -10C during nights. I remember feeling cold but it wasn't that extreme.

Then in my twenties I moved to a warmer, near the sea place where a cold winter is when you get 2/3 Celsius degrees in the coldest night and after a few years of that life, now when I go back the place where I was born in winter, I feel fucking cold (and I have special winter jackets for that).

My anecdote is the other way around. I was born in the subtropics, grew up w/o A/C. It never got below freezing.

I moved to a colder climate. The first few years I complained that the summers were never hot enough. I expected and wanted to walk out of an A/C'ed building into a wall of heat and humidity.

Now I'm used the colder weather, and find 15C/60F to be a wonderfully comfortable temperature.

And nowadays I find winter is the only season to visit where I grew up, if I want to feel comfortable.

I figured it wasn't epigenetics or some such, but rather that your body could adapt to it. I remember once when it was -23C/-10F for a week then warmed up to -10C/14F. I rolled the windows down on the car because I felt so warm ... and then I noticed the bank thermometer and was surprised.

It's fairly normal for different people to prefer different temperatures, and to a large extent it's probably a learned thing. In particular, the idea of what normal room temperature is varies quite widely around the world.

Not OP, but my wife and I are both quite thin and have no health issues. She is always colder than I am.

I think one of them is a woman.

From experience I can say that it works. Simply by using different clothes (as you described, t-shirt vs multiple layers). The only people who really struggle with no heating homes are those who need colder temperatures to sleep. I had several guests who complained that they'd like it cooler at night than during the day. However, that's not really possible if the house isn't really heated anyway and thus won't lose heat during the night.

Sometimes this is down to "micro" draughts rather than the temperature. Currently, I am sitting in about 19 degrees C inside and that should be plenty warm but in my T-shirt, I can feel very low level cold draughts caused by windows, small gaps etc. and some people are definitely more sensitive to these.

As others have said though, you can hopefully find a suitable temperature that both of you accept and it won't cost as much to keep it there.

It's the opposite for us; I'm the one feeling cold, while my wife is comfortable. I started wearing a layer of thermal underwear in the cold seasons to compensate.

For me, socks did the trick. I never had cold feet but always felt colder than colleagues in the office. An additional layer of socks made me feel warm enough to agree with the others on a thermostat setting. Still amazes me how much of an effect this had.

The human body doesn't "expect" anything, it simply must maintain its core temperature. If the temperature of the environment goes lower, the body responds by

1) increasing thermogenesis, i.e. convert chemical energy to heat through metabolism

2) reducing heat loss through the extremities by reducing blood flow there. In other words, you get cold feet and hands etc.

For people not bothered by cold, presumably it's mostly (1). For me, being skinny and not having a big appetite, it seems to be mostly (2). I suppose I could get used to having cold extremities half the year. But why suffer if I can simply put on an extra layer of clothing? I don't see the point.

but you can change what temperature you are comfortable with. i have experienced that myself. coming from an area with cold winters and heating, moving to an area without heating, i found winters absolutely horrible because despite mild temperatures outside, having those same temperatures inside was unbearable. until i got used to it. more or less.

recently i visited a friend in the north who had heating. but he complained that their heating was not good enough, and i saw him wearing a jacket inside. i, on the other hand, felt very comfortable because his weak heating was warmer than my no heating.

likewise in milder climates people start to put on winter coats when the temperature drops a few degrees outside, while i, used to much colder temperatures am still running around in a t-shirt much longer than everyone else.

the primary problem with it being cold inside is that you are not moving enough. while i am fine to have no heating in most of the house, i am heating my office because there i am sitting for many hours without moving much.